David WE Roberts :
If I need to check or modify the wiring at some future date, whatever
system I use I will have to be able to get at it all.
So AFAICS it is either having everything coming down into the ceiling
rose (and still needing access from above to e.g. add another light) or
having a simple light fitting and some kind of junction box in the
loft.

Can you position the junction box on a wall? Then you wouldn't need
access through the floor.

--
Mike Barnes