GOZO kicks off the week…
A mostly straightforward solve, though there were a few tricksy clues, and a couple of things I’d never heard of.
Thanks GOZO!

ACROSS
1. Boosts for mobility aids (3-3)
LEG-UPS
4. Stomach complaint from police department in oasis, floundering (8)
ACIDOSIS
CID (police department) in (OASIS)* (*floundering)
9. Pressed on — ride off (6)
IRONED
10. More desperate for company, lecturer removed touch of naughtiness from joke (8)
LONELIER
L (lecturer) + ONE LI[n]ER (joke, removed N[aughtiness] (touch of))
11. Wild street dog (6)
SETTER
12. The class destroyed their bags (8)
SATCHELS
(THE CLASS)* (*destroyed)
13. Some of the elvers — only this one is adult (3)
EEL
14. Stops ringing me, which improves things (6)
EMENDS
17. Coastal wet mist in Kent and Sussex after being unsettled (3,4)
SEA FRET
SE (Kent and Sussex) + (AFTER)* (*being unsettled)
21. Medal for England’s Lucy (6)
BRONZE
Double definition (Lucy Bronze being an England footballer)
26. Fishes sailor’s caught all by himself (8)
ABALONES
ABS (sailor’s) caught ALONE (all by himself)
27. Individual around cypress, say, ablaze (2,4)
ON FIRE
ONE (individual) around FIR (cypress, say)
28. Sailing around cay before night out (8)
YACHTING
(CAY)< (<around) before (NIGHT)* (*out)
29. Oppressiveness of the wig abandoned (6)
WEIGHT
30. Head over after liturgy’s slow passage (8)
RITENUTO
(NUT (head) + O (over)) after RITE (liturgy)
31. Heavy messy dog in messy place (6)
STODGY
(DOG)* (*messy) in STY (messy place)
DOWN
1. Broadcast listener received in part of Ireland (8)
LEINSTER
2. Picturesque caves where little piggies are under filth (8)
GROTTOES
TOES (little piggies) under GROT (filth)
3. Falsely claims before nurses (8)
PRETENDS
PRE (before) + TENDS (nurses)
5. Singing in bath ultimately in the pink (6)
CHORAL
[bat]H (ultimately) in CORAL (pink)
6. Germany’s empire is dismal (6)
DREICH
D (Germany) + REICH (empire)
7. Took possession of Devizes, laid waste, five missing (6)
SEIZED
(DE[v]IZES (V (five) missing)* (*laid waste)
8. Highlight singular hair (6)
STRESS
S (singular) + TRESS (hair)
12. Spell of finess regularly producing my own photos (7)
SELFIES
S[p]E[l]L [o]F [f]I[n]E[s]S
15/25 Across. Go mad as result of committing serious foul? (3,3)
SEE RED
Double (cryptic) definition
16. Fly catcher seen in WWW (3)
WEB
WWW being the world wide WEB
18. Wing and tail feathers missing one short month (8)
TRANSEPT
TRA[i]N (tail feathers missing I (one)) + SEPT (short month)
19. Crazy, like a door hanging loose (8)
UNHINGED
Double (cryptic) definition
20. Lectern reconstructed at start of year, just a few weeks ago (8)
RECENTLY
(LECTERN)* (*reconstructed) at Y[ear] (start of)
22. Orban’s successor with small monthly tale cut short (6)
MAGYAR
MAG (small monthly) + YAR[n] (tale, cut short)
Hungarian Prime Ministers
23. Weapon from Knight of the Round Table — look out! (6)
LANCET
LANCE[lo]T (knight of the round table, LO (look) out)
24. Get on with this, you understand? (6)
COTTON
COTTON ON meaning to understand
25. Paper money turned up for eating apple (6)
RENNET
(TENNER)< (paper money, <turned up)
Comment #1
Enjoyable; no particular favourites.
Is acidosis a stomach complaint? When I looked it up it said otherwise, although an upset stomach could be one of several symptoms. Never heard of a SEA FRET, and the relevance of Kent and Sussex was missed by someone so far away. In 1d, is received serving any purpose — except the surface? New to me LEINSTER, DREICH, Lucy Bronze and this meaning of RENNET.
Liked LONELIER, ABALONES, STODGY, UNHINGED and COTTON.
Thanks Gozo and Teacow.
Completed this one over my morning coffee. I live in LEINSTER so that was a write in, with most of the other clues falling in soon after. I struggled in the south west corner, putting in MAGYAR because it seemed to be the only word that could fit. (I recalled it from my stamp collecting over 40 years ago!) I still don’t understand why MAG- means small monthly. Oh, I just got it… magazine?
Thought acidosis was a blood issue, not a stomach thing
Quite easy and great fun. NHO
Lucy Bronze, SEA FRET or ACIDOSIS but all swiftly fell into place.
Thanks Gozo and Teacow.
Mainly easy but some tricky ones an nhos sprinkled in.
Doesn’t this solver normally throw in something tricksy/ theme-like? Can’t find anything today.
Thanks both.
GDU @2 and Mark A @5 – you’re correct, ACIDOSIS is a metabolic condition associated with a low blood or tissue pH, and in everyday clinical use definitely does not refer to a ‘Stomach complaint’, even though the stomach secretes hydrochloric acid. Unless the setter or editor knows something that I don’t, this looks like a boo-boo to me – famous last words! A pity as this was an enjoyable puzzle, with Lucy BRONZE (someone who could well appear again) and RENNET as an ‘eating apple’ both new to me.
Thanks to Gozo and Teacow
James @7
Aha!
What GDU@2 and SM@6 wrote
Thanks Gozo and Teacow
A fairly quick solve, despite the grid being almost four mini-grids (what another crossword site terms a ‘Brompton’ grid). We too were doubtful about the definition of ACIDOSIS; there’s also a typo in the clue for12dn – ‘finess’ should be ‘finesse’.
Enjoyable, nevertheless. Favourites were RITENUTO and LEINSTER. Thanks, Gozo and Teacow.
Gozo@9 made me look again for something, but I think I failed: the only slight pattern I could identify was that there are quite a few “ones”, forwards or backwards, in the across answers – ir0NEd, lONElier, brONzE, abalONEs, ON firE, ritENutO and also some “tens”, mostly in the downs – riTENuto again, preTENds, traNsEpT, laNcET, renNET. There must be more to it than that, though.
As Perplexus notes there are a few ‘one’s and ‘ten’s. There’s also ‘dos’, ‘sette’, ‘onze’, ‘acht, ‘eight’, ‘ein’, ‘otto’, ‘drei’, ‘seize’, ‘elf’, ‘sept’, ‘cent’ and others too, perhaps.