Times 26980 - but do they speak 13 in 3 (or 17 or 23)

Solving time: 17:17. I struggled mightily with this one, but it was all because I was unfamiliar with much of the general knowledge - the other other three times that are in so far are similar to mine. There's seven proper nouns in the grid, which seems higher than we usually have.

Apologies if this has already been mentioned, but there's a new word puzzle in the Times online. It's five cryptic clues, and instead of giving you a crossword, there's the letter bank that the answers contain. It's a different twist - I suspected RR writes the clues, and makes for a fun 1-2 minute break during the day.

Definitions are underlined

Away we go...

Across
1	Glib learner in pub is transformed with ale (9)
	PLAUSIBLE - L inside an anagram of PUB,IS,ALE
6	Own silver on table at last (5)
	AGREE - AG(silver), RE(on), (tabl)E
9	Revolutionary drink sweetheart uncovered? (5)
	KIROV - KIR(drink), then the inside of LOVE(sweetheart)
10	Loading at sea keeps ship in rapid passage (9)
	GLISSANDO - anagram of LOADING containing SS(steamship)
11	One readily turns extremist joining faction (4,3)
	WING NUT - NUT(extremist) beside WING(faction)
12	Devil that is heartless model for irreverence (7)
	IMPIETY - IMP(devil), IE(that is), then TOY(model) missing the middle
13	Speech coming out of our mouth? (7,7)
	ESTUARY ENGLISH - cryptic definition
17	Old city has loyal citizens, in for exercise (14)
	CONSTANTINOPLE - CONSTANT(loyal) then PEOPLE(citizens) with IN replacing PE(exercise)
21	Almost unrestricted speed in run (7)
	OPERATE - OPE(n)(unrestricted) RATE
23	State in which a priest entertains a bishop (7)
	ALABAMA - A LAMA(priest) containin A, B
25	Fellow brought to court with daughter shivers (9)
	MATCHWOOD - MATCH(fellow), WOO(courty), D(daughter)
26	Message online and call from branch? (5)
	TWEET - double definition
27	Bit embarrassed evidently by second husband (5)
	SHRED - RED(embarrassed) by S, H
28	Dreadful crustacean in river drained lake (9)
	EXECRABLE - CRAB(crustacean) in EXE(river) and L(ak)E

Down
1	US writer and editor welcoming Kew grower (8)
	POKEWEED - POE(US writer), and ED containing KEW
2	Item with Oedipal strings attached? (5)
	APRON - cryptic definition
3	Drinkers drinking still in Kentish Town? (9)
	SEVENOAKS - SOAKS(drinkers) containing EVEN(still)
4	Huge effort required to admit old prejudice (7)
	BIGOTRY - BIG TRY (huge effort) containing O
5	Rabble-rousing lacks initial impression (7)
	EDITION - SEDITION(rabble-rousing) missing the first letter
6	Storyteller sending up main work (5)
	AESOP - SEA(main) reversed, OP
7	We weren't first knights wicked pursuer's trapped (7-2)
	RUNNERS-UP - N,N(knights in chess) inside an anagram of PURSUER
8	Silhouette's one small horse breaking into dash (6)
	EPONYM - PONY(small horse) inside an EM dash.  The word is derived from Etienne de Silhouette
14	We're toast having rolled vehicle (3-6)
	TWO-SEATER - anagram of WE'RE TOAST
15	Edmund Crouchback say thrown in road by king (9)
	LANCASTER - CAST(thrown) inside LANE(road), R(king). Edmund Crouchback was Earl of Lancaster
16	Theatre skill doubled energy in comic dialogue (8)
	REPARTEE - REP(theatre), ART(skill) then two E's
18	Fantastic doctor to close with thread over in A&E (7)
	AWESOME - MO, SEW(close with thread) all reversed in A and E
19	Loveless pair become confused in silly talk (7)
	TWADDLE - remove O from TWO, ADDLE(become confused)
20	Foremost among minds that cracks cases? (6)
	HOLMES - an all-in-one. M(inds) inside HOLES(cases, scrapes, situations - at least that's my best guess).  I got an email suggesting that it is M inside HOLES(cracks, solves), which sounds a bit better.
22	Climbing pea's tips concealed plant pest (5)
	APHID - P(e)A reversed, then HID(concealed)
24	Serve Republican British bitter (5)
	ACERB - ACE(tennis serve), R(republican), B(British)