Across:
8 Commentators dismiss Castro (‘commentators’ dismiss ‘Castro’ = omment = MOMENT) for short time (for the MOMENT),
9 Private (PERSONAL) trains (= anagram indicator) or planes (or planes = PERSONAL)
10 Matt (DULL) sides with Duke of Argyll (sides with ‘DUke of ArgyLL’ = DULL),
11 Cite a visit (cite a visit) planned (= anagram indicator) (cite a visit = ACTIVITIES) with things to do (ACTIVITIES),
12 Fit in (BELONG) with a follower (‘a’ follower = B-), for example (e.g. = -E-G), consuming port (port/left = -L-) that’s not off (not off is ‘on’ = -ON-) (BELONG),
14 Monitor (OBSERVE-) resistance (-R) (OBSERVER) from witness (OBSERVER),
15 Briefly loses it (MOMENT OF MADNESS) in 8 across (‘moment’ = MOMENT) going around (O-) France (-F) – a state of confusion (MADNESS) (MOMENT OF MADNESS),
18 Funny (STRANGE-) writing (from 3Rs = -R) (STRANGER) in The Outsider (STRANGER),
20 Got a flavour of (TASTED) oils no longer in solid state (‘oils’ no longer in ‘solid state’ = dstate = TASTED),
22 Still (MOTIONLESS) got nothing to raise at the meeting? (no motion = MOTIONLESS),
24 Brunette left Buster Keaton (‘brunette’ left ‘Buster Keaton’ = skao = SOAK) to relax in the bath (SOAK),
25 Criminal (= anagram indicator) snipers (snipers = PRIN-ESS) caught (-C-) inside (PRINCESS) might still have a shot at the monarchy perhaps? (PRINCESS),
26 Did some pressing work (IRONED) for Oscar (-O-) in new (= anagram indicator) diner (diner = IR-NED) (IRONED).
Down:
1 Sound (VOLUME) of the bookmaker (VOLUME),
2 Put in the picture (TELL) on both sides of ten dollar bill (on both sides of ‘TEn dollar biLL’ = TELL),
3 Frank (STRAIGHT) Blunt? (STRAIGHT),
4 Catch sight of (SPOT) The Borders’ tourist traps (the borders ‘TOurist traPS’ = tops) coming back (= reversal indicator) (tops = SPOT),
5 Finishing beer (finishing ‘beeR’ = -R-) in seedy bar (D-IVE-), skinhead (‘Skin’ head = -S) (DRIVES) takes to the road (DRIVES),
6 The types likely to walk all over (FOOTPRINTS) part of crime scene that the police consider as evidence (FOOTPRINTS),
7 Casual (CARELESS) mini (CAR-) with elegant top (‘Elegant’ top = -E-) is reduced (-LESS) (CARELESS),
13 Into (into = -TION-) pop? (= anagram indicator) Consumed by musical dramas? (operas = (OPERA-S) (OPERATIONS) You’ll see these all in the theatre! (OPERATIONS),
14 Proposal (OFFER) for volunteer? (OFFER),
16 A way (away = OUT-) for opening (-DOOR-) beers at the foundation (‘beerS’ at the foundation = -S) (OUTDOORS) exposed to the elements (OUTDOORS),
17 Creative (ARTISTIC) awful (= anagram indicator) racist (racist = ARTIS-C) admits twisting (= reversal indicator) it (it = -TI-) (ARTISTIC),
19 Take sign from sniggering (take ‘sign’ from ‘sniggering’ = gering= GINGER) local red head (GINGER),
21 Cleared (ERASED) out of Red Sea (red sea) craft (= anagram indicator) (red sea = ERASED),
23 Is not demanding (is EASY) a piece of cake (EASY),
24 Outlet (SHOP) for posh (posh) model (= anagram indicator) (posh = SHOP).