@JimHowell1970
Thanks for chiming in! I’m using the Quadratt and Duatt as modulation mixers, offset and polarizers.
The current case is 7U on the first link, meaning the bottom 3U row is the coming skiff.
They would of course stay in one of the 1U rows in the big system! ;)

I have a switch incoming (and I’m really looking forward to it), when one of the ceis gets to the shop, as they were bought at the same time...

The matrix mixer is something I’m really considering, as it’s such a good way to open up modulation possibilities, as you said! Do you have any preference?