check page 3 from that pdf,
there is some info how to convert signals 1 and 2, to mono. find bridge W400 and w401.
i’ve desolder that bridge and solder 2 way switch.
if i wanna use Btl, mono mode, just set correct position of that switch and connect main out xlr left to icepower input 1, and then same main out xlr fight from kemper to icepower input 2, but with modified xlr cable, just replace two hot wires inside.
you can see some about that on page 22 of that pdf.
i hope it’s clean how i wrote lol