Is there any reason I shouldn't continue the circuit from the last socket
back to the fusebox (adding the odd socket here and there) to turn it into
a ring?

In fact, you must do this to make it compliant. A 2.5mm radial clipped
direct should be fused at 20A. A 2.5mm ring can be fused at 30A. Better
still, use a B32A RCBO instead of a fuse. Much safer, particularly for power
tools.

Christian.