ACROSS
 1. DISSER VICE = DISSERVICE <wrong>
 6. <ripped> BUFF <khaki>
 8. CROQUE[-t] (RIO MENU'S)* = CROQUE MONSIEUR <sandwich>
10. MANI _A_ = MANIA <craze>
11. (ROSE WHITE)* = OTHERWISE <if not>
13. R AIDER = RAIDER <invader>
15. <they legislate> ALDERMEN = ALDER MEN
18. NONE outside A LOX = NALOXONE <treatment for overdose>
21. <check> REIN IN = RE (IN IN)
23. <compromises> TRADE-OFFS = ←SF FOE DART←
25. <racecourse> EPSOM = EP SOM_
26. (LORD OF THE RINGS)* = LONGSHORE DRIFT <geological process>
28. <truant> AWOL = _O_ inside AWL
29. TEMPER ANC E_ = TEMPERANCE <anti-alcohol ideology>

DOWN
 1. <collection of stories> DECAMERON = DE CAMERON
 2. →"BOON SPILL"← = SPOONBILL <wader>
 3. EMU LATE = EMULATE <parrot>
 4. VI _M TO = VIMTO <drink>
 5. <scam> CON <right-winger>
 6. <combat> BOER WAR = "BORE WORE"
 7. <divine> FORESEE = "FOUR" SEE
 9. <narrow> SLENDER = S LENDER
12. <robber> TEA LEAF = _TEAL_ _E_ _AF_
14. <rowdy> RIOTOUS = RIO (TO US)
16. (MUSINGS IN)* = MINUS SIGN <dash for takeaway?>
17. (RENAME TON)* = NANOMETRE <metric unit>
19. <current> AIRFLOW = ⭯FAIR⭯ LOW
20. <e.g. first> ORDINAL = O RD IN A_L
22. <writings seen here> E-READER = ERE A DER
24. SUP outside YR = SYRUP <sweet liquid>
27. U inside HE = HUE <tone>