Use Steinberg UR816c with RME RayDat and Apogee AD/DA16

I have an RME RayDat on a windows 10 computer with Cubase Pro10.5 and Wavelab Pro 10. There is a main PCIe board with ADAT 1 and 2 in/out connected to the Apogee channels 1-16 running 24bit 44.1Khz. There is also an expansion board with ADAT 3 and 4 in/out not being used. I am interested in adding more channels of in/out and also the option for 192 KHz and 32bit.

Would adding UR816c units work well together with this system?

How many channels of in/out possible?

What bit rate and what frequency options?

If I want to do 32bit 192k how would I do it?

Thanks for ant help.