I felt I made heavier weather of this than it warranted, taking a neat 23 minutes, but since that’s less than three Vs it may be more taxing that that. There are also an appreciable number of single mistake entries, though I can’t see a likely candidate for a common error.
I’ll give credit to the setter for making sure the musical term in 3d is the process of reaching a loud noise rather than the more common solecism of the loud noise itself, though I suspect that’s one of the error in language that will become accepted through much use. Otherwise, and with the probable exception of 1ac, there is little to tax the vocabulary of most of this company, and in a few cases the wordplay borders on the simples.
I have produced a rundown of the entries and how to get there, with clues, definitions and SOLUTIONS.
1 Tree so great shelters the old woman (6)
SUMACH You can be forgiven for not knowing this tree, even if it is “any tree or shrub of the genus Rhus, esp R. coriaria; the leaves and shoots used in dyeing.” I can’t find any previous appearance even in MCS and Mephisto. So trust the wordplay: you know the old woman is MA and scratch around for SUCH as equivalent to “so great”, then assemble. Apparently, some varieties of sumac(h) fruit can be ground and used to make a form of pink lemonade
4 One coming in to cite holy writ, the result of division (8)
QUOTIENT I (one) is entered into cite: QUOTE and NT will do for the (back end) of holy writ.
10 Two sides bordering study covered in pleasant flowering plant (6,3)
GOLDEN ROD So not Aaron’s rod, then. Two sides are L and R, placed either side of study: DEN and then planted in GOOD for pleasant.
11 Exist as a dissenter in the party (5)
BEANO If you act as a dissenter you would BE A NO.
12 Face a revolutionary’s self-assurance (7)
PANACHE I got the revolutionary first, because it’s almost always Ernesto Guevara , known to his mates as CHE. PAN is slang for face, and the A is there in plain sight.
13 Situation for highest-level worker? (7)
ROOF-TOP Barely cryptic definition.
14 Polish novel given English translation finally (5)
SHEEN See novel, think Rider Haggard’s SHE. Add E(nglish) and “finally” translatioN.
15 Metal objects in club with damage through use reportedly (8)
IRONWARE a golf club, and the sound (reportedly) of WEAR for damage though use.
18 Gent, sorry when falling short, working to be sturdier (8)
STRONGER Much easier than I thought. An anagram (working) of GENT SORRY with the Y chopped as it falls short.
20 Old king left some of the food offered by butcher? (5)
OFFAL You old king is OFFA, he of the dyke, add L(eft)
23 Truck carrying litres for one who likes a drink or two? (7)
TIPPLER The truck is a TIPPER, the inserted L comes from L(itres)
25 Dodgy cult with unique feature for those buying into it (7)
SUSPECT Cult is SECT and the rest put into it is Unique Selling Point
26 Football club has managed to save money in Switzerland? (5)
FRANC Still used in Switzerland, so no messing about with “former”. The F(ootball) C(lub) has RAN for managed saved.
27 Discovered part of Peru near the desert (9)
UNEARTHED Well hidden in PerU NEAR THE Desert
28 Time in coastal location where wild flowers can prosper? (3-5)
SET-ASIDE Part of the Common Agricultural Policy in Europe meant that farmers were paid not to grow stuff on set-aside land leaving it open to nature’s own efforts. Just put T(ime) into SEASIDE as the simplest of coastal locations, and add a hyphen
29 Number bunked off in gutless endeavour (6)
TWENTY Take the guts from TRY for endeavour, and you get TY. Insert WENT for bunked off.
1 Highlight what PA would ask boss to do before email? (8)
SIGNPOST I suppose this means that, before the boss retreats into the daily trawl through emails, the PA would ask them to sign to snail mail stuff so that they could entrust it to the pillar box. Or maybe our setter has electronic signing in mind: don’t email until you do. Maybe.
2 This writer leads the way, penning good collection (7)
MELANGE This writer: ME comes before the way: LANE with a G(ood) inserted.
3 Second race, with number two going badly as the roar goes up? (9)
CRESCENDO First take out the number 2 (letter) of RACE, then run the remains and SECOND through your randomiser (going badly).
5 Hundreds in Europe sadly having no exercise and lacking good food (14)
UNDERNOURISHED An anagram (sadly) of HUNDREDS IN EUROPE. [I forgot to mention that you need to remove the PE from the end of EUROPE - because it "lacks exercise" - before throwing the letters into the mixer. Thanks Vinyl]
6 Out putting label on ducks (5)
6 Out putting label on ducks (5)
TABOO That meaning of out. Label: TAB plus two 0’s masquerading as letters.
7 Bringer of law, measure that performer must follow (7)
ENACTOR EN is the measure (of type space) and performer is ACTOR
8 One band or another being heard (6)
TROUPE What it says it is, sounding a lot like TROOP
9 See nerd undergo big change in place fostering new ideas? (8,6)
BREEDING GROUND Another long anagram (change) of NERD UNDERGO BIG. Both Collins and Chambers prefer the term as an environment generating undesirable rather than the more anodyne “new” developments. Universities are a breeding ground for the corona virus – who’d have thought it?
16 Forest's team in domestic fixture (9)
WOODSCREW Quite literally something which fixes in domestic (and of course other) situations. It’s just forest’s: WOOD’S team: CREW
17 Running behind time, heading off with great excitement (8)
ELATEDLY I assume this is just BELATEDLY beheaded.
19 For prominent one on board, tribute entertaining political leader (7)
TOPMAST A political leader is what our current PM might like to be. Tribute: TOAST is what we need to “entertain” him with. Whatever keeps him happy.
21 Soldiers shut up in the bog get spruced up? (7)
FRESHEN Soldiers RE plus shut up: SH placed in bog: FEN
22 County workers in a number of offices? (6)
STAFFS Short for the county of Staffordshire, and also the people who occupy several offices.
24 Place offering food for preacher John — without end (5)
LOCUS Preacher John is the Baptist, who dined healthily on LOCUSTs and wild honey. Remove the end from the crunchy bit of his diet.