it's too early to accept less exciting return in such perfect surroundings (9)
I believe the answer is:
premature
'it's too early' is the definition.
(I've seen this in another clue)
'to accept less exciting return in such perfect surroundings' is the wordplay.
'to accept' indicates putting letters inside.
'less exciting' becomes 'tamer' (I've seen this in another clue).
'return in' says the letters should be written in reverse (I've seen 'returning in' mean this).
'such perfect surroundings' becomes 'pure' (I can't explain this - if you can you should give a lot more credence to this answer).
'tamer' written backwards gives 'remat'.
'remat' inserted inside 'pure' is 'PREMATURE'.
Can you help me to learn more?
(Other definitions for premature that I've seen before include "Born before full term" , "not fully developed" , "Too soon to cause me rapture" , "Rash" , "Before the normal time" .)