ACROSS
 9. "ROCK + FOUR" = ROQUEFORT <blue cheese>
10. VOL inside _OO_ = OVOLO <architectural feature>
11. <exploit> USE = US E
12. (RATHER NOBLY)* = ABHORRENTLY <inspiring disgust>
13. <charlie's follower> DELTA = _D + LATE*
14. CHURRO outside AS C = CHURRASCO <grilled steak>
17. ↺MANATEE↺ = EMANATE <spring>
19. <wise> SAPIENT = SAP IE N_T
21. F + RIZZ + NEAT* = FRIZZANTE <bubbly>
23. ←CAN← H O = NACHO <tortilla snack>
25. (JIVE OVER EID)* = JOIE DE VIVRE <exuberance>
27. <gas> AIR = A_ IR
28. <country> KENYA = ENYA after _K
29. TIN DER BOX = TINDERBOX <volatile person>

DOWN
 1. <mince> GROUND BEEF = →"BOUND GRIEF"←
 2. <sing> SQUEAL = (.e)SQUE AL(b.)
 3. <context> METADATA = ←AT A DATE + M←
 4. (SOHO outside P) CLEAN = SOPHOCLEAN <sort of Greek drama>
 5. <lead> STAR = S + TAR
 6. ←RUE SOP← = POSEUR <impostor>
 7. <French noblewoman> COMTESSE = COME outside TESS
 8. <tiny> BONY = BO[-n]NY
15. <tenacious> UNSWERVING = UN SERVING outside W
16. (OR THORAX + Y) outside P = ORTHOPRAXY <performing correct rituals>
18. <making excuses for> ALIBIING = ALI BING outside I
20. P_ _INCEN_ EZ = PINCE-NEZ <spectacles>
22. <Gemini etc> ZODIAC = ←(.i)C AI DOZ(e.)←
24. <irritated> CRABBY = CRY outside A (B B)
25. JOE outside K = JOKE <gag>
26. <stop> VETO = VET + _O_