The message
from Stuart contains these words:

As I understand it, you can only have a single fitting off a spur. So
/two/ double sockets on one spur is out.

One double on each of two different sockets should be OK.

The latter is what I understood to be the OP's intention ...

I thought so too - which was why mentioned it!

--
Skipweasel
Pay no attention to that man behind the curtain.