Times 23456

[devadiva]

25a=Competence revealed by match point (7) T?T????
20d=Long range signal originally heard on radio (6) ?I?R?A
16d=Express at rear of platform two finally departed (8)
?A?I???T
17d=Overruled what the answer to the final clue might be (8) ?E?E???ED
This is probably Saturdays crossword and too far to scroll back to see if they have ben answered - apologies if they have.

[crofter]

20d Sierra (mountain range) = S(ignal) on "air"?

[crofter]

25a looks like FITNESS -check your T
Fit (match) + ness (point / headland)

[kayakamina]

17d Reversed.....the final clue is 'refer ' a palindrome!

[kettledrum]

Manifest - manifest(o)

[crofter]

Well done -I've been double K-ed

16d I'd just got MANIFEST but could not work out the clever word play.
As for 17d - I was working on an ENDER finish!? Ugh

[devadiva]

Many thanks for your help and apologise for lateness of answer - I had to go out