ARTEXLEN kicks off the week…
A couple of things I’d not come across before (17a and 14d), but gettable nevertheless. A fun Monday morning puzzle.
Thanks ARTEXLEN!

ACROSS
1. Prefer a vino initially in square (6)
FAVOUR
(A + V[ino] (initially)) in FOUR (square)
5. Fast food from kebab shop includes a wrap regularly (8)
SHARPISH
SHISH (food from kebab shop) includes (A + [w]R[a]P (regularly))
9. Chose food Pret prepared (5,3)
OPTED FOR
10. Mate shortened very large trousers (6)
CHINOS
CHIN[a] (mate, shortened) + OS (very large)
11. Get together to understand (6)
GATHER
12. Friend eventually carries case for aunt (8)
INTIMATE
IN TIME (eventually) carries A[un]T (case for)
13. Easily negotiates small troubles, nevertheless maintaining resistance (5,7)
SAILS THROUGH
S (small) + AILS (troubles) + THOUGH (nevertheless) maintaining R (resistance)
17. Spray cologne around pipe-inspecting tool (12)
LARYNGOSCOPE
(SPRAY COLOGNE)* (*around)
20. Restricts criminal associate before offence (6,2)
FENCES IN
FENCE (criminal associate) before SIN (offence)
23. Beginning to shave, picks up clippers (6)
SHEARS
S[have] (beginning to) + HEARS (picks up)
24. Commend Napoleon’s third advance (6)
PRAISE
[na]P[oleon] (third) + RAISE (advance)
25. Allowing some vagrant in garden (8)
GRANTING
[va]GRANT IN G[arden] (some)
26. Stand untangling pet’s lead (8)
PEDESTAL
(PETS LEAD)* (*untangling)
27. Station American enters somewhere near Windsor (6)
EUSTON
US (American) enters ETON (somewhere near Windsor)
DOWN
2. Rise of climber planted in April (6)
APPEAR
PEA (climber) planted in APR (April)
3. Extremely rash having bears in open yard (9)
OVERHASTY
HAS (bears) in OVERT (open) + Y (yard)
4. Overhauling online class, perhaps, taken in group (9)
REFORMING
(E-FORM (online class, perhaps)) taken in RING (group)
5. Raids store is to resolve (7)
SORTIES
(STORE IS)* (*to resolve)
6. Neckwear son found in crumpled coat (5)
ASCOT
S (son) found in (COAT)* (*crumpled)
7. Legendary leader, Prime Minister possesses elevated demeanour (5)
PRIAM
PM (Prime Minister) possesses (AIR)< (demeanour, <elevated)
8. In coastal area, identify poverty (8)
SHORTAGE
in SHORE (coastal area), TAG (identify)
14. Reptile circles plain endlessly (4-5)
HOOP-SNAKE
HOOPS (circles) + NAKE[d] (plain, endlessly)
15. Dramatic works poet rates poorly (9)
OPERETTAS
16. Having no worries about heartless official (8)
CAREFREE
CA (about) + REF[e]REE (official, heartless)
18. Commando receives information about foreign land (7)
SENEGAL
SEAL (commando) receives (GEN)< (information, <about)
19. Pair working almost too quickly (6)
PRONTO
PR (pair) + ON (working) + TO[o] (almost)
21. Name of fellow with nasty cold returning (5)
CLIVE
(EVIL (nasty) + C (cold))< (<returning)
22. Small amount of money for the French perfume (5)
SCENT
S (small) + CENT (amount of money for the French)