I’d love to help but i don’t understand what you are trying to say:
“Ctrlr bug at fx1 and send data infinitely to synth and freeze while this create an infinite fast flux of chksum errors on the synth”
what is FX1, nothing will be sent “forever” unless you told Ctrlr to do that, a feedback loop might happen not only due to bugs in Ctrlr but due to bad Lua method, you need to make sure that your methods are loopback safe, create some checks for recursion etc.