ACROSS
 1. <preparing for future> FORESIGHT = FIGHT outside ORES
 6. <ascent> CLIMB = LIMB after C
 9. <consolidate> UNIFY = UNI F_Y
10. ←(.m)ETALLIC SO(d.)← = OSCILLATE <to be unstable>
11. G A_ + SLIGHT = GASLIGHT <illumination>
12. <house> PISCES = PI S_C_E_S
14. CIA + O_ = CIAO <later>
15. <advantageous> PROFITABLE = PRO FABLE outside IT
18. ALLEGE outside I ANC = ALLEGIANCE <loyalty>
19. <Rhenish white> HOCK <meat>
21. PUT RID = PUTRID <off>
23. <amphitheatre> COLISEUM = (MUSE CLIO)*
26. GEN ITALIA[-n] = GENITALIA <privates>
27. "TRACKED" = TRACT <pamphlet>
28. <number> ETHER = (ET HER)
29. OPPRESSOR* = PROPOSERS <those bending the knee?>

 1. <cast> FLUNG = LUNG after F
 2. REINS TALL = REINSTALL <put back in position>
 3. <block> STYMIE = ST + Y_M I_E
 4. <type of power plant> GEOTHERMAL = (.a)GE OTHER MAL(f.)
 5. TA CO = TACO <Mexican food>
 6. <nymph> CALLISTO = (CALLS TO) outside I
 7. I ←AS← AC = ISAAC <Biblical figure>
 8. <meat> BEEFSTEAK = BEEF'S TEAK
13. A FIC[-t]ION + ADO = AFICIONADO <lover>
14. CHAMP + AG NE = CHAMPAGNE <celebratory drink>
16. BROKER AGE = BROKERAGE <financial business>
17. AG LITTER = AGLITTER <brilliant>
20. BIRO outside S_T = BISTRO <café>
22. <fish> TENCH = R out of TRENCH
24. MAT HS = MATHS <subject>
25. <short video> CLIP <fast pace>