Cursory look (I'll have to fully read it later to check more)
Supply from bike into the IN route obviously, which the OUTS paired in earth one side of board opposite the positive side, six channels in all.
Optimate charge cable IN wouldn't be routed through this board, as far as I can see. Supply and protection for that is inntge Optimate unit and going direct into battery on vehicle.
The central section of fuses, control by fuse placement, as to whether each circuit it static feed with ignition on OR with the fuse flipped from one gang to the other will provide a switched line. Switching is on this board in that case, it looks like. This should take place ofca relay by solid state switching on this board ..... is there a remote control for this board ? Whichbwouod give you direct "relayed" feed to item in that case.
I'll get to read it through later to correct what I've put there, perhaps there's personal experience on here to help too.