Bitfile or help – Mesa 6i25 + 7i74 (BiSS-C) + 8i20 + 7i70/7i87

Hello,I am new to LinuxCNC and Mesa hardware and I am working on a relatively large project. Before going further, I would like to ask for advice to make sure I am approaching the configuration correctly.
I am on a linux 4.19.0.21 -rt - amd64 smp preempt rt debian.
My hardware configuration: Mesa 6i25 (PCIe) Connected via P3 (external connector) to a Mesa 7i74. It is intended to interface a signal BiSS-C from a RAIK060 BiSS-C rotary encoder used for motor position feedback. A mesa 8i20 Powerdrive for the motor associated with the BiSS-C encoder. A mesa 7i70 and a mesa 7i87 are used for another part of the project: Temperature sensor, Pressure sensor and one servo motor.
II am planning to build a custom wiring setup using a RJ45 cable to carry the BiSS-C signals. To connect this cable to the first RJ45 port on the 7i74.
Current status: I have tried modifying an existing VHD file as a starting point, however I am not confident that the overall architecture is correct or my intended usage. What I am looking for is general guidance on the recommended architecture for this combination of cards ( a bitfile would also be perfect ) any advice on a suitable firmware for the 6i25 + 7i74 (BiSS-C), any pitfalls to avoid or best practices for a setup of this size. I understand this is a complex setup for a beginner, but I would need help and be thankful for your time and help.

Bitfile (and changed source)  for 5i25/6i25 with 7I74 and 4 sserial channels and 4 BISS channels:

 

Pretty sure Tommylight has some example files using SSI feedback (which is very similar at the HAL level)

Thank you for your help, I'll check that right away.