Across
Solver's finally happy, hour after hour (4)
I haven't cracked this one yet — but Fifteensquared have:
Y (last or ‘final’ letter of happy) + h OUR (letters of ‘hour’ after the ‘h’ (hour))
Cold water pitcher occasionally emptied (3)
I haven't cracked this one yet — but Fifteensquared have:
Alternate letters (‘occasionally emptied’) in pItChEr
One who plays recordings of river bird (6)
I haven't cracked this one yet — but Fifteensquared have:
DEE (river) JAY (bird)
After endless uncertainty, final couple leaves less aggressive bid (6)
I haven't cracked this one yet — but Fifteensquared have:
DOUB t (uncertainty) missing last letter or ‘endless’ + LE ss (final couple leaving). We checked this in Chambers and think it must come from the phrase ‘double or quits’.
Reportedly prompt party waited in line (6,2)
I haven't cracked this one yet — but Fifteensquared have:
A homophone (‘reportedly’) of CUE (prompt) + DUP (party)
The other side of fat in beef or vegetable (4)
I haven't cracked this one yet — but Fifteensquared have:
BEE f – replacing ‘f’ with T – the other end or ‘side’ of ‘fat’
Flustered fellow unhinged when credit denied (5)
I haven't cracked this one yet — but Fifteensquared have:
F (fellow) cr AZED (unhinged) without ‘cr’ or ‘with credit denied’
Win ultimately - make America greater again (4)
I haven't cracked this one yet — but Fifteensquared have:
The last or ‘ultimate’ letters of makE AmericA greateR agaiN
A backward period (3)
I haven't cracked this one yet — but Fifteensquared have:
A reversal (‘backward’) of ARE (A, as in the metric measure of area)
Provide with sustenance feel seed lacks otherwise (4)
I haven't cracked this one yet — but Fifteensquared have:
FE el se ED without or ‘lacking’ ‘else’ (otherwise)
Wrestling team's able lead? (4,5)
Bloomer by leading player: eat this, fail drug test (5,4)
I haven't cracked this one yet — but Fifteensquared have:
POPPY (‘bloomer’) SEED (leading player)
Arch American exclaiming "Oh, goodness me!" (4)
I haven't cracked this one yet — but Fifteensquared have:
A homophone (‘exclaiming’) of Oh Gee! – the way that an American may say ‘Oh goodness me!’
Relay without start or finish (3)
I haven't cracked this one yet — but Fifteensquared have:
s END (relay) without the first letter or ‘start’
Change after stripping over here (4)
I haven't cracked this one yet — but Fifteensquared have:
o VE r h ER e (both words missing first and last letters or ‘stripped’)
Live operating locks in Limehouse (2,3)
I haven't cracked this one yet — but Fifteensquared have:
ON (operating) h AIR (locks) dropping the ‘h’ – as might be heard in Limehouse (East End of London)
Took a year to collect fine (4)
Large woman massaged in stages (8)
To start with Elon and Trump together abandoning Detroit's legal rights (6)
I haven't cracked this one yet — but Fifteensquared have:
E and T (first letters or ‘starts’ in Elon and Trump) missing from or ‘abandoned by’ D et ROIT’S
Tent peg with cupped top leads to leak (6)
I haven't cracked this one yet — but Fifteensquared have:
TEE (peg with cupped top) PEE (leak)
Question of motive with case of heresy (3)
I haven't cracked this one yet — but Fifteensquared have:
W (with) H eres Y (first and last letters only or ‘case’)
Part of London somehow losing seabird in two separated areas (4)
I haven't cracked this one yet — but Fifteensquared have:
SO me HO w missing ‘mew’ (seabird) in two separate places
Down
Three oxygen atoms linked circle and sphere (5)
I haven't cracked this one yet — but Fifteensquared have:
O (circle) ZONE (sphere)
Berated after exchange of bishop and rook discounted (7)
Indescribably top-to-toe fine, fine and well (9)
I haven't cracked this one yet — but Fifteensquared have:
FINE F (fine) with the first letter moving to the bottom or ‘top-to-toe’ + ABLY (well)
How you might address a man in picturesque parts (3)
Shudder at the thought of defunct dressing recipe (5)
I haven't cracked this one yet — but Fifteensquared have:
DEAD (defunct) around or ‘dressing’ R (recipe)
Maybe 18 chosen troops to oust leader of Cuba (7)
I haven't cracked this one yet — but Fifteensquared have:
ELE c T (chosen) with MEN (troops) replacing C (Cuba)
Article's disheartening dispute over the French painting technique (9)
I haven't cracked this one yet — but Fifteensquared have:
A (article) QUA r Rel (dispute) missing the middle letter or ‘disheartening’ + LE (French for ‘the’)
Temperature in Azores damaged seagrass (7)
I haven't cracked this one yet — but Fifteensquared have:
T (temperature) inside an anagram (‘damaged’) of AZORES
Once, quietly, permit setter's padding word (9)
I haven't cracked this one yet — but Fifteensquared have:
EX (once) P (quietly) LET (permit) I’VE (setter’s as in setter has). We had to check this as we were not aware that an ‘expletive’ can be a word included merely to fill a gap, or to fill up a sentence or line in verse.
Odder plays, with many contemporary (6-3)
Cut below average veg (7)
Stinking? Almost strange, funny smell having been eliminated (7)
I haven't cracked this one yet — but Fifteensquared have:
OD d (strange) missing last letter or ‘almost’ + hum OROUS (funny) missing or ‘eliminating’ ‘hum’ (smell)
Nothing wrong with the old Earl atop beautiful thing in bed (5)
I haven't cracked this one yet — but Fifteensquared have:
O (nothing) X (wrong) + YE (old version of ‘the’) with E (earl) above or ‘atop’
A bit much, initially losing increasing numbers of letters that 'Arry's dropped (5)
I haven't cracked this one yet — but Fifteensquared have:
Mmmmmm! A b IT mu CH (increasing the initial dropped letters from 0, 1 to 2). We’re not sure that we like ‘Arry’s dropped’ as a definition for AITCH
Tool used to be set up (3)
I haven't cracked this one yet — but Fifteensquared have:
A reversal (‘set up’) of WAS (used to be)
Type letters or click words in the clue