Thoughts have turned to distribution of the DCC power/signal and the carving up of power districts.  I've arrived at the following:

The grey boxes, top left, are circuit breaker boards,  They receive the DCC power/signal from the NCE Master Panel and the power is split into three power districts, each with their own circuit breaker...cicuitry.

#1 District serves the upper fiddle yard and teh hidden main-line track all the way to the lift out section.

#2 District serves the whole of the branch, including the lower fiddle yard, the hidden branch line and Clarencekirk proper.

#3 District 3 serves The hidden Main-Line/Virtual Carriage sidings from the lift out section to St Catherine's Bay and St Catherine's Bay proper.

The black rectangles on these busses are distribution boards connected to the track dropers.

Daisy chained to the NCE Master panel are four more DCC panels to enable flexible control options.

If I can finalise this arrangement, it means I can get the busses and DCC cables installed before the baseboard tops go on.

I still have to look at the best arrangement for the positioning of the Megapoints circuit boards....