Fifteensquared

A fairly standard Cincinnus puzzle this week with at least one great clue (3D) and one that I do not understand the workings of (26D).

Across
1. THE WASP FACTORY - anagram of OF CREW THAT PAYS. “The Wasp Factory” is a book by Iain Banks — not that I had ever heard of either title or author. I figured it had to be either THE WASP FACTORY or PET WASH FACTORY and a quick google confirmed the former.
10. HORSE - double definition with a sneakily good surface
11. SIMULATOR - anagram of LITMUS OR A
12. TRESTLE - anagram of LETTERS
13. ROMANOV - ROMAN (Pompey the Great, say) + OV (over half)
14. PLUMB - homophone
16. CUTTING IN - double definition
19. CONSENSUS - homophone (cons’ census)
20. ERASE - A (article) in ERSE (Gaelic)
22. ACCUSED - A (a) + CC (cricket club) + USED (employed)
25. AUCTION - AU (gold) + anagram of COT IN
27. SNAKE EYES - double definition
28. RATES - tRuAnT fEeS
29. CURTAIN RAISERS - anagram of RUNS AS CRITERIA

Down
2. HARLEQUIN - HARE (run) around L (lake) + QUIN (one of 5)
3. WHEAT - E (energy) in WHAT (eh)
4. SESTERCES - anagram of CERES SETS
5. FEMUR - EMU (bird) in FR (father)
6. COLUMBINE - COMBINE (wed) with LU (Lake Superior) inserted
7. ORTON - hidden word
8. YEREVAN - ERE (before) in NAVY (sailors) backwards
9. SHUT UP - double definition
15. BEERSHEBA - BEER (bitter) + SHE (female) + BA (graduate)
17. TASMAN SEA - MAN (chap) in TASS (new agency) + EA (Eastern area)
18. GLADIATOR - GLAD (happy) + I (infantry) + A (vanguard) + TOR (hill)
19. CLASSIC - LASS (girl) + I (one) in CC (leaders of cross country)
21. ERNEST - homophone (earnest)
23. CHAIR - double/cryptic definition
24. DOYEN - DO (suit) + YEN (foreign currency)
26. CORPS - ???. I do not understand the wordplay here — but see the Comments section