Sometimes I find it difficult to think of something to say in the preamble and today is one of those occasions. As usual, there were some new words, for me, but nothing that couldn’t be determined from the wordplay once some checkers were in place. I think my favourite new word today is 28ac, though 23dn is not far behind.
Across
1 Still to aim as arranged for highest summit (12)
ALTALTISSIMO – an anagram (arranged) of STILL TO AIM AS
10 Pilot yielding opening for traveller (6)
VIATOR – [a]VIATOR (pilot yielding opening)
11 Share / port (5)
SPLIT – double def.
14 Flap greeting overwhelming demand (9)
AVENTAILE – AVE (greeting) around (overwhelming) ENTAIL (demand)
15 Electronic instrument’s tinkling stopped by simple turning (8)
THEREMIN – THIN (tinkling) around (stopped by) MERE (simple) reversed (turning)
16 Rich and stupid, losing 1000 dollars (4)
OOFY – [g]OOFY (stupid, losing 1000 dollars)
18 Coastal state with fine space created by mining (4)
GOAF – GOA (coastal state) F (fine)
20 Swiss city, fashionable European starting point (8)
BASELINE – BASEL (Swiss city) IN (fashionable) E (European)
21 Bad book in sense without force in boring part (5,3)
DRILL BIT – ILL (bad) B (book) in DRI[f]T (sense without force)
24 Day’s work necessary to end argument (4)
DARG – hidden in (necessary to) ‘enD ARGument’
26 Handle a shell (4)
PAWA – PAW (handle) A
28 Left partner with joke and caress (8)
LALLYGAG – L (left) ALLY (partner) GAG (joke)
29 Bit sorry, put away passionate intensity (5,4)
WHITE HEAT – WHIT (bit) EH (sorry) EAT (put away)
30 In no case take uniform back (5)
NEVER – R (take) EVEN (uniform) reversed (back)
31 Criminal taken in possession of large chain (6)
ANKLET – an anagram (criminal) of TAKEN around (in possession of) L (large)
32 Cat active around bed missing nothing in bush (12)
PROSTANTHERA – PANTHER (cat) A (active) around RO[o]ST (bed missing nothing)
Down
2 Greedy person on strike, man breaking settled rule for printer (12)
LITHOGRAPHER – HOG (greedy person) RAP (strike) HE (man) in (breaking) LIT (settled) R (rule)
3 Tormented by fate, waste away (6)
TABEFY – an anagram (tormented) of BY FATE
4 Appealing area covered by river, volume rising (8)
LOVEABLE – A (area) in (covered by) ELBE (river) VOL (volume) reversed (rising)
5 Orifice that remains in part (5)
TREMA – hidden in (in part) ‘thaT REMAins’
6 Philosophers disown pieces with odd bits deleted (6)
IONICS – [d]I[s]O[w]N [p]I[e]C[e]S (disown pieces with odd bits deleted)
7 Spring above wild glen in sparkling spot (7)
SPANGLE – SPA (spring) plus an anagram (wild) of GLEN
8 One with trouble lifting bones (4)
ILIA – I (one) AIL (trouble) reversed (lifting)
9 Insipid fellow, accommodating type, weak in engagement? Right (12)
MILK-AND-WATER – MAN (fellow) around (accommodating) ILK (type) plus W (weak) in DATE (engagement) R (right)
12 Fleet involved with madness in transport system (9)
TELFERAGE – an anagram (involved) of FLEET plus RAGE (madness)
13 Broadcast, entertaining until eccentric withdrew (5,4)
STOOD DOWN – SOWN (broadcast) around (entertaining) TO (until) ODD (eccentric)
17 Gasp, carrying instrument, upset and irritable (8)
PETULANT – PANT (gasp) around (carrying) LUTE (instrument) reversed (upset)
19 Altogether old-fashioned group commander raised, holding line (7)
ALGATES – SET (group) AGA (commander) reversed (raised) around (holding) L (line)
22 Composer, endlessly advanced creator (6)
BRAHMA – BRAHM[s] (composer, endlessly) A (advanced)
23 Soldier in area between hills able to move about (6)
VAGILE – GI (soldier) in VALE (area between hills)
25 Fresh colt, not fat (5)
CLEAN – C (colt) LEAN (not fat)
27 Lively current, see, in middle of Avon (4)
VIVO – I (current) V (see) in [a]VO[n] (middle of Avon)
There were a couple I couldn’t parse, so thanks for the explanations. 2dn I had all the bits, just couldn’t fit them together in my head, and 24ac where I’m kicking myself for missing such an obvious hidden answer.