I found this installment from Slormgorm rather a stiff challenge . . .
. . . with quite a few clever misdirections. I hope I have explained everything adequately, but we can sort things out in the comments, if necessary.

| ACROSS | ||
| 1 | ACCURATE |
Faithful copper that a cold judge locks up (8)
|
| {A + C (cold) + RATE (judge)} around (locks up) CU (copper) | ||
| 5 | SHEATH |
Passion checked by extremely smallish condom (6)
|
| HEAT (passion) inside (checked by) outside letters of (extremely) S[MALLIS]H | ||
| 10 | EGOISTS |
We love US sites and go all over the place (7)
|
| Anagram of (all over the place) {SITES + GO}, with a capitalization misdirection | ||
| 11 | EARNEST |
Serious ecstasy to have a holiday around June 3rd (7)
|
| E (ecstasy) + A + {REST (holiday) around the third letter of (3rd) [JU]N[E]} | ||
| 12 | OBSERVANT |
Vigilant man in pursuit of odious British leaders (9)
|
| First letters of (leaders [of]) {O[DIOUS] B[RITISH]} + SERVANT (man) | ||
| 13 | MONTH |
Period in which insect cocoons finally open (5)
|
| MOTH (insect) around (cocoons) last letter of (finally) [OPE]N | ||
| 15 | SIEVE |
One’s lying about the First Lady showing strain (5)
|
| I’S (one’s) reversed (lying about) + EVE (whimsically the first lady), with a capitalization misdirection | ||
| 16 | TANK TRAP |
Bronze mouth lined with 1,000 dragon’s teeth? (4,4)
|
| {TAN (bronze) + TRAP (mouth)} around (lined with) K (1,000), referring to a type of anti-tank obstacle | ||
| 19 | PROTRUDE |
Sex worker discourteous about tenor’s bulge? (8)
|
| {PRO (sex worker) + RUDE (discourteous)} around (about) T (tenor) | ||
| 20 | EIDER |
Duck and fish served in every restaurant at front (5)
|
| IDE (fish) inside (served in) {first letters of (at front) E[VERY] R[ESTAURANT]} | ||
| 21 | EARTH |
Want no end of Chambord? Here you are! (5)
|
| [D]EARTH (want) minus (no) last letter of (end of) [CHAMBOR]D | ||
| 23 | PLEASURES |
Super ale brewed by son gives a good time (9)
|
| Anagram of (brewed) {SUPER ALE} + S (son) | ||
| 25 | COCONUT |
Shy constituent cross about old Conservative (7)
|
| I think this parses as: CUT (cross) around (about) {O (old) + CON. (Conservative)}, referring to the fairground game, with the shared sense of “cut” and “cross” being something like “intersect” | ||
| 27 | TRACHEA |
Airline chart altered by European head of airline (7)
|
| Anagram of (altered) CHART + E (European) + first letter of (head of) A[IRLINE], with a whimsical definition | ||
| 28 | LABOUR |
What might occur sometime after sex party (6)
|
| Double definition | ||
| 29 | ENTELLUS |
Monkey found in screen? Tell usherettes! (8)
|
| Hidden in (found in) [SCRE]EN TELL US[HERETTES] | ||
| DOWN | ||
| 1 | ALEHOUSE |
A large assembly interrupted by English boozer (8)
|
| {A + L (large) + HOUSE (assembly)} around (interrupted by) E (English) | ||
| 2 | CROSSBEARER |
You might say The Messiah bores carers stupid (11)
|
| Anagram of (stupid) BORES CARERS | ||
| 3 | RESURGENT |
Ploy queen brought up to get chap rising again (9)
|
| {RUSE (ploy) + R (queen)} all inverted (brought up) + GENT (chap) | ||
| 4 | TESLA |
Time beer’s knocked back, including small unit (5)
|
| T (time) + {ALE (beer) inverted ([is] knocked back) around (including) S (small)} | ||
| 6 | HAREM |
Group of kept women from Perth are man-eaters (5)
|
| Hidden in (from) [PERT]H ARE M[AN-EATERS] | ||
| 7 | ACE |
Whizz is speed, but not PCP ultimately (3)
|
| [P]ACE (speed) minus (but not) last letter of (ultimately) [PC]P | ||
| 8 | HITCH |
Problem husband gets with restless desire (5)
|
| H (husband) + ITCH (restless desire) | ||
| 9 | SENTENCE |
Awareness that one will have to depart life? (8)
|
| SENT[I]ENCE (awareness) minus (that . . . will have to depart) I (one), referring to a prison term | ||
| 14 | NEANDERTHAL |
An old man (other than an elder) (11)
|
| Anagram of (other) THAN AN ELDER, with a whimsical definition | ||
| 16 | TRUMPETS |
“Aliens will not come first here!” President proclaims (8)
|
| I think this parses as: ETS (aliens) after (will not come first here) [Donald] TRUMP (President) | ||
| 17 | TREE SNAKE |
A keester erupts without warning? Essentially I’m a windy beast! (4,5)
|
| Anagram of (erupts) {A KEESTER} around (without) middle letter of (essentially) [WAR]N[ING], with “windy” in the sense of “sinuous” | ||
| 18 | TRESPASS |
Father and son could break lock to do this (8)
|
| semi-&lit and {PA (father) + S (son)} inside (could break) TRESS (lock) | ||
| 21 | EXCEL |
Cap old church put on laymen primarily (5)
|
| EX- (old) + CE (church) + first letter of (primarily) L[AYMEN] | ||
| 22 | HINDU |
One who believes you must track deer (5)
|
| U (you) after (must track) HIND (deer) | ||
| 24 | EATEN |
Corroded and battered sheds close to prefab (5)
|
| [B]EATEN (battered) minus (sheds) last letter of (close to) [PREFA]B | ||
| 26 | CUB |
Rookie Chelsea possibly left out of its line-up (3)
|
| C[L]UB (Chelsea possibly) minus (out of its line-up) L (left) | ||
CUB was the only one I couldn’t parse, along with 3d, for which I’d wrongly entered RESURRECT. ENTELLUS & TANK TRAP were new to me. All else fell into place and was enjoyed.
All went in pretty easily except for Tank Trap. Couldn’t fathom that one out.
Hesitated over sentence but realised it was the only answer.
Thank you Slormgorm and Cineraria.
I too made the mistake of Resurrect rather than Resurgent. Thought Rect must be something to do with Rector😔😔
Otherwise it all fell fairly steadily until getting stuck for quite some time on Tank Trap and Sentence, before they finally fell.
Lots of fun and I must admit I loved Harem.
Thanks to SLORMGORM and Cineraria.
I’m never sure of the extent to which misleading punctuation can be justified. It took a long time for me to parse 17 TREE SNAKE because the N is one of those “essentially” clues (which I won’t complain about again) and the word “essentially” was firmly installed in a different part of the clue from the word “warning”, separated from it by a question mark. I suppose that’s OK but I’m not very happy about it.
I found the SW corner tricky, not helped by getting 28 wrong, assuming that “party” was “do” and that the answer was, for some reason I couldn’t parse, “libido”. A clever clue in a good puzzle.
Challenging but all gettable, although we couldn’t parse COCONUT and needed to check ENTELLUS inn the dictionary. LOI was 9dn where we eventually realised how the clue worked but took a while to decide if the definition was ‘life’ or ‘awareness’. Favourite was TRACHEA.
Thanks, Slormgorm and Cineraria
I had an unparsed RESURRECT too. I blame the presence of CROSSBEARER as a parallel answer.
Took me a long time to get EGOISTS. I was convinced it was something like AMOROUS when I had the O and S crossers. Nice misdirection with US.