Three unclued lights featured the remaining ones, two of two words, the others paired. Two of them do double duty. Elsewhere, ignore one circumflex.
 

Across

7/7D Part of microscope under old coach (8)
11    Country house’s grand spread (6)
15    This is very slow, taking only a second to catch (5)
16    Pretentious fellow taken to court, reportedly (5)
17    Hold prisoner and bury at noon (6)
18    Rubber rope (5)
20    Possibly 22’s special ceremony (6)
21    Entrance halls where amateur match gets cut (5)
22    Upset goldminer spurns do for troublesome creature (7)
27    Mathematical array from graduate taking a moment (7)
29    Put to use some cheap plywood (5)
30    Bush,...