Thanks to Anto. Definitions are underlined in the clues.
Across
1 Reserve able to control movements in very large area (12)
SUBCONTINENT : SUB(short for “substitute”/a reserve player in a competitive team) + CONTINENT(able to control one’s bowel and bladder movements).
9 Women’s section starts to have arts review every month (5)
HAREM : 1st letters, respectively, of(starts to) “have arts review every month“.
Defn: Formerly, … /a separate part of a Muslim household reserved for wives, concubines and female servants.
10 Spot equipment getting picked up for display (9)
SPECTACLE : Homophone of(… getting picked up/heard) [“speck”(a small spot of colour) + “tackle”(equipment required for a task, inclusive of a man’s genitals)]
… though I wouldn’t pronounce the 2nd syllable of “spectacle” as I would “spectacular” or the 1st syllable of “tackle”.
11 Seize one chance to have joint control (2-5)
CO-PILOT : COP(to seize/to catch) + I(Roman numeral for “one”) + LOT(chance/a random selection, as in “to decide the winner by lot”)
12 Check before discharge (7)
PREVENT : PRE-(prefix meaning “before”/prior) + VENT(to discharge or expel through an outlet).
13 Research facility is abandoning inaccessible treatment (7,3)
SCIENCE LAB : Anagram of(… treatment) [“is” deleted from(abandoning) “inaccessible“].
15 Fight to have water source back (4)
SPAT : Reversal of(… back) TAPS(devices for controlling the flow of/sources of water).
18 Meter maid is grim dictator at heart (4)
RITA : Middle 2 letters, respectively, of(… at heart) “grim dictator“.
Defn: “Lovely Rita”, the parking meter maid/traffic warden in the Beatles song.
These Lovely Sheila meter maids Down Under (Surfers Paradise) top up your parking meters instead:
19 Fool was confused by overturned vote? That’s rubbish (10)
CODSWALLOP : COD(a foolish person) + anagram of(… confused) WAS + plus(by) reversal of(overturned) POLL(a vote/an election).
22 Successful record in register (3,4)
HIT HOME : HIT(a successful record/song, one in the hit parade) + HOME(in, as in “I’m home most of the time”).
Defn: …/to make an impression on a person’s mind.
24 Clear reprimand when spades lost by worker (7)
BLATANT : “blast”(a reprimand/a scolding) minus(when … lost) “s”(abbrev. for “spades”, the playing card suit) plus(by) ANT(any of a family of social insects, that include the worker caste).
25 Ace airman moving stuff from the US (9)
AMERICANA : Anagram of(… moving) ACE AIRMAN.
26 Love a noted couple (5)
ADORE : A + DO,RE(syllables representing a couple of notes in the sol-fa music scale).
27 Literary lady makes change after mob made a mess (6,6)
MADAME BOVARY : VARY(to change/to modify) placed after(after) anagram of(… mess) MOB MADE A.

Down
1 Sensitive issue excited open riots (4,5)
SORE POINT : Anagram of(excited) OPEN RIOTS.
2 Inferior jewellery is a bit gauche (8)
BUMBLING : BUM(inferior/of poor quality) + BLING(expensive and ostentatious jewellery).
3 Start off unprepared? Quite the opposite (5)
ONSET : ON(not off/Quite the opposite of “off”) + SET(prepared/ready/Quite the opposite of “unprepared”).
4 They perform plays initially in ramshackle shanties (9)
THESPIANS : 1st letter of(… initially) “plays” contained in(in) anagram of(ramshackle) SHANTIES.
Defn: … in stage-plays.
5 Knock over stone cask to get spice (6)
NUTMEG : Reversal of(Knock over, in a down clue) [GEM(a precious stone) + TUN(a large beer or wine cask)].

6 Inlay carved regularly from this material (5)
NACRE : 2nd, 4th, 6th, 8th, 10th letters of(… regularly) “Inlay carved“.
Defn: Aka mother-of-pearl
7 Gets rid of Charlie’s chickens (6)
CHUCKS : Triple defn…. I think. 2nd: CHUCK(nickname for Charlie)‘S; and 3rd: an Americanism for “food”, including chickens?
I’m probably off-track.
8 Half scrambling is something you can do with an egg (4,2)
BEAT IT : 1st 5 letters of(Half) “scrambling“/scram!/BEAT IT!
Defn: … to blend the yolk and white.
14 Clear old boyfriend on single charge (9)
EXONERATE : EX(an old/former boyfriend) placed above(on, in a down clue) ONE(single) + RATE(a charge/a fee paid for services).
Defn: … of an accusation/a charge.
16 Loving lots of people providing fantastic playroom above yard (9)
POLYAMORY : Anagram of(fantastic) PLAYROOM placed above(above, in a down clue) Y(abbrev. for “yard”, unit of measurement of length).
17 Doubled up per diem to produce boring talk (4,4)
YADA-YADA : 2x(Doubled) reversal ofup …) [A DAY](per diem, as in “a fee of $100 per diem”).
Defn: …, probably from “yatata”/idle chatter, in turn from “yatter-yatter”/chatter.
18 Try again to bring up having ambassador arrested (6)
REHEAR : REAR(to bring up young/offspring) containing(having … arrested) HE(abbrev. for “His/Her Excellency”, form of address for an ambassador).
Defn: … in a court of law.
20 Too much entered for each craftsman (6)
POTTER : OTT(abbrev. for “over the top”/too much) contained in(entered) PER(for each, as in “a rate per day”).
21 Cheer on opera star, one who appeared naked (6)
GODIVA : GO!…( expression used to cheer on somebody, as in “go, man, go!”) + DIVA(a celebrated female opera singer/star).
Defn: The legendary Lady who went bareback riding through the streets of Coventry, in protest and nothing else.

23 Article that oddly describes character from Athens (5)
THETA : THE(a grammatical article) + 1st and 3rd letters of(… oddly) “that“.
Defn: Character in the alphabet used in Athens.
24 Party can make one negative (5)
BEANO : BE(make/become, as in “he will make a good singer”) + A(one) + NO(a negative answer or decision).
Defn: Short for “beanfeast”.
Thanks Anto and scchua
I enjoyed this – lots of clues to make me smile. I’ll mention SPECTACLE, SCIENCE LAB, GODIVA,and BEANO.
Shouldn’t 15a be “sources” rather than “source”? It wouldn’t make any difference to the surface.
RITA would be a bit opaque to anyone who didn’t know Sergeant Pepper!
I agree, lots to like here. In addition to those mentioned by muffin, I ticked HAREM and BEAT IT. Thanks to Anto and scchua.
Not convinced by definition 3 of “chuck”. There is an animated TV series called “Chuck chicken” which might be the reference. But I think that “chuck” is just a familiar name for chick. We keep hens and often call then for food by calling “chuck, chuck”! An OK quiptic with several nice clues. Thanks all.
When I ask for eggs at my butcher’s, he always says “6 chukkies coming up”! (short for “chukkie – or chuckie? – eggs. Local dialect?)
Must have been tempting for an Aussie to ,put in CHOOKS instead of CHUCKS-but for the crosser,
Thanks, scchua. I’m sure you’re on the ball with the CHUCKS clue. It’s a pity ONSET was in today’s Quick, also defined as “start”. I don’t understand why HOME is “record” in 22a.
And SPECTACLE is nowhere near a homophone of SPECK TACKLE, unless you’re putting on the accents in O Brother where art thou?
Only HIT is record, HOME is in.
I found this tough, and dnf. I did get RITA, though, despite not knowing the context. I got it from the rhyme, thought she might be from a seventies advert or TV show or something.
Thanks to sschua and Anto
I have northern relatives and they routinely call a chicken a “ch—k”, (I’ve not asked them they spell it).
They also ask me if I’d like a ch—ky egg with my breakfast, and, though tempted, I’ve not asked which others they have available.
I think the first def here includes “of”.
I found this quite difficult. I failed to solve HIT HOME, BEANO.
My favourites were POTTER, BUMBLING, ADORE.
New for me was POLYAMATORY.
As an Australian, I am more used to see the word chooks for chickens. When I looked it up (chook), I found this:
“ORIGIN 1920s: probably from English dialect chuck ‘chicken’, of imitative origin.”
I failed to parse BEAT IT.
Thanks Anto and scchua.
I do love this site. If I give up on a puzzle I can find out all the things I didn’t know. I can take solace in the fact I rarely find myself kicking myself for an obvious miss.
It does strike me that sometimes the main crossword is at the level I’d expect of a quiptic, and vice-versa. I found this one a lot harder than the main Guardian cryptic from the other day (whose setter I forget)
Bum Bling. That was excellent.