I totally forgot this was a Friday and submitted in 5 minutes something before realising my error. Oh well, no harm done! I did find a lot of the clues very, as they say, biffable from a couple of crossers, but they were mostly rather nicely turned, so no grousing from me tonight. COD to 27ac which made me chuckle, and I also very much appreciated the historical &littery of 15dn. Thanks setter for a nice puzzle!
In other news -
topicaltim and I are getting an online quiz league team together, wanna join? It would totally suit someone who just wanted to dip their toe into the murky waters of quizzing for the first time, and would require only a sporadic commitment to logging into Zoom and answering questions for half an hour on the occasional evening. If you are even half interested, definitely hit us up! The honour of Times for the Times is at stake...
ACROSS
1 A fine considerably limits current liaison (6)
AFFAIR - A F(ine) FAR "limits" I. Why is "I" the symbol for current, I suddenly thought to myself? Apparently it was the choice of M. Ampere, and stands for current Intensity.
4 Diner supplied sandwiches, building support (8)
SCAFFOLD - CAFF "sandwiched" by SOLD [supplied]. Much easier to get from the definition than by struggling with the cryptic, I'd have thought.
10 Left old friend casing clubs in the area (7)
LOCALLY - L(eft) O(ld) ALLY, "casing" C(lubs)
11 Find spice regularly in the Orient? Nothing's simpler (7)
EASIEST - S{p}I{c}E in EAST
12 I don't give a fig about southern party (4)
BASH - BAH! about S(outhern)
13 Bloke's not entirely likeable group's breaking camp (10)
HISTRIONIC - HIS NIC{e}, broken by TRIO
15 Happy union's no-score draw? (4,5)
LOVE MATCH - suggesting something different when converted into sportsese.
16 Baby carriers, say, losing temperature, one concludes (5)
UTERI - UT{t}ER, concluded by I [one]
18 Noble Oscar shed clothes (5)
BARON - O(scar) "clothed" by BARN [shed]
19 Custody battle ended shortly after flu got out of control (3-2-4)
TUG-OF-LOVE - OVE{r}, after (FLU GOT*)
21 Pity old queen having to face cross physicist (10)
RUTHERFORD - RUTH [pity (old)] + E.R. + FORD [cross]
23 Stuck first of borrowed money in Oslo (4)
BORE - B{orrowed} + ORE. A krone is divided into 100 øre, not that you see many of those any more.
26 Deadlock: four leave showing no emotion (7)
IMPASSE - IMPASS{iv}E
27 Catty Pope? (7)
LEONINE - as in Leo IX
28 For which tours are organised? (8)
EUROSTAR - (TOURS ARE*), semi-&lit27
29 Let special medical team cut open Marxist? (6)
RENTED - E.N.T. "cut open" RED
DOWN
1 A German tabloid's taken over with no preparation (2-3)
AD-LIB - A + reversed BILD
2 Husband abandons razor perhaps that preserves his dignity? (4-5)
FACE-SAVER - FACE-S{h}AVER
3 Indulged in odd places between jobs? (4)
IDLE - I{n}D{u}L{g}E{d}
5 Fastest runner caught - he can't stand up (7)
CHEETAH - C + HE + reversed HATE [can't stand]
6 Doubt about chopped ice in packs for boxing (10)
FISTICUFFS - reversed IF [doubt "about"] + IC{e} in STUFFS [packs]
7 Drink drug in round tin (5)
OCEAN - E in O CAN
8 Dick, not working, takes female out for a short time (9)
DETECTIVE - DE{f->T}ECTIVE
9 Pool worker one goes in to look up in Times (6)
TYPIST - I "goes in" reversed SPY, in T, T
14 Copier a chap uses in novel (10)
AMANUENSIS - A MAN (USES IN*)
15 Large individual, Edward VII acquiring name as this (9)
LIBERTINE - L I BERTIE "acquiring" N, semi-&lit
17 Green film about operating organ (9)
ECONOMIST - ECO MIST "about" ON. Organ as in periodical
19 Lifted plump cheese to find crisp material (7)
TAFFETA - reversed FAT + FETA
20 Swill King George brought up, breaking wind (6)
GARGLE - reversed G.R. "breaking" GALE
22 Wax cylinder recorder (5)
TAPER - double def
24 Editor recruits staff to do what he does (5)
EMEND - ED "recruits" MEN, semi-&lit
25 Forty winks? Just under twelve (4)
DOZE - DOZE{n}