Hello,
I can't help you much, but I'll give you a couple of ideas to keep in mind.
Each blind needs 2 relays. Open - Close.
Each shutter needs 2 inputs to detect opening and closing.
Depending on the type of motor you buy, the Open and Close detectors are already built-in, you do not need inputs to the control PCB. Keep that in mind and save money.
And if you want, as a precaution, use local control buttons on each blind (it will be useful at times, but you will be glad to have it).
For now, I leave these duties to you and someone with more experience to contribute on the control system.
Best regards
What you don't know ... Question !! and what you know ... Share !! - By Joan