Here you have a crossword that is a fine addition to the “explosion in a Scrabble tiles factory” genre, with a large number of words seemingly deliberately selected for how unlikely they look. For me at least, the way solving something like this goes is thinking, “hmm, the wordplay here could result in this unlikely looking word… could it possibly be real”? I don’t think there’s any shame per se in Googling to see if a “rya rug” is actually a real thing, or if “tarboggin” is really an antiquated spelling of “toboggan”, or “wanty” can somehow mean belt, or various deeply foreign words are actually legit and not just massively wishful thinking on your part. You could just submit with half a dozen pairs of fingers and toes crossed, but is that really more moral than checking? I don’t personally see an argument for saying that solvers should be expected to know the vocabularies of Spenser, Scotland, taxonomy and the nations of Asia in advance of solving these puzzles.
Any, with all that said – I had seen about half of the words in this grid before, or had enough of a glimmer of recognition to put them in with relative confidence, including my FOI 10ac and the likes of AGNAIL, EPIZEUXIS, ADDAX, GLIRES, ULIKON, PEAG, LWEI and LUSTRUM. But hell yeah I looked up some of the other words for confirmation, just in case. As a result the puzzle took a little over 20 minutes and was very enjoyable throughout. I think my COD is the pleasingly self-referential 23ac (despite the normalness of its answer), but I liked ROSE TO LA PAZ, the return TO OZ, and the great surfaces of the likes of 14ac and 24ac. Hugest thanks to the setter, for another very fine and special monthly treat!
Definitions underlined, (ABC)* indicating anagram of ABC, {} deletions and [] other indicators.
Across
1 Authority briefly needed to conceal beam, turning back floor covering (3,3)
RYA RUG – GUR{u} “concealing” RAY, the whole reversed
4 Long game: minutes becoming several years! (7)
LUSTRUM – LUST R.U. M [long | game | minutes]
9 What’s in sarnie on and off: fast food (5)
SEHRI – EH? in S{a}R{n}I{e}. “Fast food” as in a pre-dawn meal during Ramadan, not the McDonalds type
10 Stump of old elm in bag, close to forester’s pants (9)
IMBRANGLE – (ELM IN BAG {foreste}R*)
11 Book for Italy today, with mountain lake setting: earlier, travel in winter? (9)
TARBOGGIN – B OGGI “set in” TARN
12 Recalled large conflict, with poet’s version of clash among Persians? (5)
WRAWL – L WAR W, all reversed. Spenserian caterwauling
13 Shade of pulse, not half making change from shells? (4)
PEAG – PEA-G{reen}. Native American shell money
14 In break after casting, film director needs fine sound quality (10)
KLANGFARBE – in (BREAK*), (Fritz) LANG + F
18 Back where scarecrow went, by chance spies untimely burial (10)
ZOOTHAPSIS – reversed TO OZ, by HAP + S.I.S.
20 Head for Luanda week ending the first, making ready there? (4)
LWEI – L{uanda} W/E I [the first, as in Charles I]. Angolan change
23 Abandons game with one of the pieces missing? (5)
QUITS – QU{o}ITS, a ring being a game piece in quoits
24 Originally, would seeing that Roman “I”, and very big “E”, do for printers? (9)
WASEGOOSE – W{ould} + AS [seeing that] + EGO [I, in latin] + O(ut)S(ize) E. A printers’ annual dinner or picnic, because obviously you need a special word for that
25 Pressing certain points home when judge leads quiet trendy to act (3,4,2)
JIN SHIN DO – IN led by J(udge), plus SH! IN DO [quiet | trendy | to act]. Some kind of acupressure technique
26 Notices, with backs turned to each other, ten antelope (5)
ADDAX – AD forwards and then backward, plus X [Roman numeral ten]
27 Old offensive one from the French Red Guards (7)
RUDESBY – DES [from the, in French] “guarded” by RUBY
28 Some mammals primarily green, like insects, others tailless (6)
GLIRES – G{reen} L{ike} I{nsects} + RES{t}
Down
1 Leaving LA, reached city much higher? One turned pink in the heat! (4,5)
ROSE TOPAZ – ROSE TO {la} PAZ
2 Religious teacher cautious, with people kicking bottle about? (7)
ACHARYA – CHARY in A(lcoholics) A(nonymous)
3 Lake, one in Canadian territory, not unknown for fish (6)
ULIKON – L(ake) I in {y}UKON
4 Dance theorist’s place to research article (5)
LABAN – LAB(oratory) + AN
5 If a sweep’s organised, she’d predict results? (8)
SPAEWIFE – (IF A SWEEP*). An oracular old woman
6 Artist and girlfriend show for kit inspection (3-4)
RAG-FAIR – R.A. and GF AIR
7 Left a lot of leaves to pick up mass of seaweed (5)
MAERL – L(eft) REAM, the whole reversed
8 Family on Greek border fish for food (8)
KINGKLIP – KIN on G(ree)K LIP
15 Fabric in centre has ink on, so ruined (8)
NAINSOOK – ({h}A{s} INK ON SO*)
16 Deliberate repetition of short narrative poem by one with God’s protection (9)
EPIZEUXIS – EPI{c} + X I [by | one] “protected” by ZEUS
17 Grass seed’s outside, another cycling to collect it (8)
KHUSKHUS – HUSK “collected” by KHUS [“cycled” HUSK]
19 Made with something naturally pungent, dogmatic, but not sanctimonious (7)
ONIONED – O{pi}NIONED
21 Staff to wind up evidently embarrassed: see, that hurts! (7)
WOOLDER – RED LO! OW!, the whole reversed
22 Digital imperfection upset Australian game-show hosts (6)
AGNAIL – hidden reversed in {austra}LIAN GA{me-show}
23 Dynasty something spoken of as line almost closed (5)
QAJAR – homophone of QUEUE + AJAR
24 Yen, in different ways, for belt no longer used (5)
WANTY – WANT [yen] + Y(en). Obsolete word for a belt securing a pack-horse’s load
As usual, a slow and steady plough through all the obscurity and obfuscation, the pleasure being very different from the usual solve.
This one slightly marred by picking the wrong alternative spelling (of many) of ULIKON: a little extra thought would have worked out the Yukon connection, but it didn’t happen.
My compliments to the setter and Verlaine the Invincible.
Midas