1. Who in Rome has time to accept rest, relaxing? One on a mission no longer QUESTRIST (anag. in quis (L.) + t) The little bit of Latin you require to solve the wordplay isn’t in Chambers, but shouldn’t be difficult to look up.
8. Examine china fragment of porcelain PALP (pal + p) The rhyming slang is well disguised in the surface sense.
13. Local crook, king in commerce briefly CROM(E) (R in com) A tricky solution until you’ve determined the central B. Even if you guessed GLOBES for the diagonal, you still have the alternative spelling CROMB to eliminate.
16. Computer storage methods left half of us space BLU-(R)AY(S) (l u(s) in bay) A regular enough plural form that probably didn’t need the footnote, but Azed is usually scrupulous in the matter of Chambers’s contents when setting specials…
23. Face switching sections in supermarket ALDI (halves swapped in dial) …although this familiar trademark (unlike Hot Topic) is not footnoted.
38. Exiles set out clutching duplicated bits of property (D)EP(O)RTS (pr in anag.) The ‘duplicated’ seems only to be indicating that two letters from ‘property’ are needed.
41. Rule book: it’s learnt in ballet school P(L)IÉ (2 mngs) This is pie4, a book of rules for Church Offices.
42. Scrape maybe set back European company in e.g. Lyon (D)E-ICE (E Cie.) ‘Cie.’ is the French equivalent of English ‘Co.’
2. Self-contained rubber instrument U(K)ULELE (ule in ule) A fortuitous unindicated letter gives Azed the chance of an entertaining piece of wordplay.
7. Order neat dress fittings TRIM (4 mngs.) Another rare opportunity is a word with 4 distinct meanings that can be arranged into a plausible sentence. In this case some of the meanings are very close semantically, but the clue works better than the similar 37 down.
10. In a hurry to grab power, biased PREPOSSESSED (posse in pressed) A concise clue for the joint longest solution in the grid, making use of a Latin rather than a Wild West posse.
11. Born cowboys maybe having met galloping round mountain spur EMBRANCHMENT (b + ranch men all in anag.) A Wild West posse does seem to feature in this next solution, however, with a good surface story.
20. Front-runner in National? Distance no longer used E(LOI)N (en) A little confusing, since an en is a measure of distance (still used) in printing, as well as a letter N. ‘Eloin’ is the old word meaning to put at a distance.
21. Sloth, something fatal for widow (S)A(T)I (ai) The crossword solver’s familiar three-toed friend makes a welcome appearance in the grid to provide the remaining letters of this alternative spelling of ‘suttee’.
24. Working out what to serve with rolls? P(A)T(S) (PT) Pats of butter might appear with bread rolls. Working out in the sense of Physical Training.
26. Water-parsnip cocktail imbibed by exclusive group SKIR(R)ET (kir in set) A roast parsnip cocktail might make interesting use of the Christmas leftovers. ‘Set’ here is used in a social rather than mathematical sense.
27. Former marriage following love not once ONE-TI(M)E (0 + ne + tie) The elements of the clue are set for maximum ambiguity, with ‘former’ as the definition, and ‘not once’ leading to ‘ne’.
34. Devotee of Demeter went off by the sound of it? (E)POPT (‘popped’) The connection to Demeter comes through the Eleusinian Mysteries of ancient Greece. Azed takes a fairly low risk in assuming the pronunciation of the non-word ‘popt’.
39. What principal has held as part of noble peerage? EPÉE (hidden) The principal here is not one that Lords might adhere to, but a principal actor, who might wield a sword at some critical point.
Across: 12. (K)ATHAK (at hak(I’m)); 14. MU(S)A (U in MA); 13. CRIN(O)SE (c + rinse); 17. (G)RIP (2 mngs.); 18. REFR(E)S(H)E(S) (r in anag.); 22. YO-YO (yo(u) yo(u)); 24. P(AUL)A (P a); 25. HUSS (hidden); 28. CAKY (k in cay); 29. T(ORI)I (initial letters); 30. TUNE (comp. anag.); 31. HAIL (2 mngs; hail2,3); 33. (S)P(I)N(E)TTES (T in anag.); 35. MAR(A) (ram, rev.); 40. EA(R)MARK (anag.); 43. SEPIU(M) (anag.); 44. TA-TA (tat + A); 45. STRETCHER (str. etcher).
Down: 3. STA(R)RI(L)Y (anag. in sty); 4. THRA(E) (hidden); 5. RACY (c in ray); 6. SCRY (sc(a)ry); 8. PON(G)Y (2 mngs.); 9. AM(O)ROUS (m in arous(e)); 19. S(ALO)P (sp.); 25. H(O)T T(O)PIC (TT in anag.); 32. L(A)MIA (L + aim, rev.); 36. SACS (C in SAS); 37. FRET (3 mngs.).