No 13781, Monday 06 Feb 2023, Arden

Three answers per commenter till 6 PM (Annotations compulsory) 

Please submit all your answers in one comment.  

Thanks for following the rule at short notice. I have updated the post.

ACROSS

1   Fish nets regularly mopped, it's slow (6) IMPEDE {I{MoPpEd}DE} 

4   Starts with blue and red - on time for a title (8) BARONAGE {Blue}{And}{Red}{ON}{AGE} 

9   Small place, they say it spreads (6) SPLAYS {S}{(~place)PLAYS}

10 Old King's edict to make a salad (8) COLESLAW {COLE'S}{LAW}

12 The sea grass covering was still there (8) REMAINED {RE{MAIN}ED}

13 Bordering Columbia, nothing in Spanish land (6) CANADA {Co...iA}{NADA}

15 A British duty, could be very revealing (8,4) BIRTHDAY SUIT*

18 Bandaged in parts, get a severe reprimand (8,4) DRESSING DOWN {DRESSING}{DOWN} 

21 Hard to fit into a small place if fat (6) CHUBBY {C{H}UBBY}

22 Quorum required for a religious service, may be I'm in many (8) MINYANIM* 

24 Probably around ten - English collection of French poems (8) RONDEAUX {AROUND+X+E}*

25 Make every effort to get a second coach (6) STRAIN {S}{TRAIN} 

26 Threaten with delivery as Sobers returns (8) BALLYRAG {BALL}{GARY<=} 

27 Quote the setter over purge (6) EMETIC {CITE}{ME}<= 

DOWN

1   Mark cooked nice ribs (8) INSCRIBE*

2   Supply more variety, throwing up chemicals (8) POLYMERS {SupPLY+MORE}* 

3   Repair rear light and body, by paying such a high price (8,7) DAYLIGHT ROBBERY*

5   No copy right on law just now (4) ANON cANON

6   Work time, set my things in order - no high Windows, perhaps (9,6) OPERATING SYSTEM {OP}{ERA}{SET+MY+ThINGS}*

7   I am agile, flexible - reportedly eyes go all shiny (6) AGLEAM {i+AM+AGiLE}*

8   Last of the prawn cooked up, cover it (6) ENWRAP {thE}{PRAWN*}

11 Gas used to destroy data stored on a hard drive (7) DEGAUSS* 

14 Keen to 11 a drug (7) ASPIRIN ASPIRINg

16 Blue feathers for the troupe (8) DOWNCAST {DOWN}{CAST}

17 First of March to third of June income varies - it will help you remember (8) MNEMONIC {Ma..h}{juNe}{INCOME*}

19 Mark on a black seal (6) SCARAB {SCAR}{A}{B}

20 Link between UK and France - came up fast including the French one (6) TUNNEL {LENT<=} over {UN}

23 Four hogsheads and a fish (4) TUNA {TUN}{A}

Reference List

Small = S, Nothing in Spanish = NADA, Down = D, Hard = H, English = E, Second = S, Copy = C, High = H,  Gauss = G, Black = B, One in French = UN