1. It says "Protocol implemented = no", but "Powers bike = yes", you can power a Bosch gen 2 motor without implementing the protocol, presumably this is referring to the CAN wire on the battery.
2. Your battery kit is 316 EUR without cells, and your BMS spare part is 99 EUR. If you can talk to Bosch motors then presumably this is where that special sauce is.
I for one might be interested in just something that serves to talk with the Bosch motor, and allows one to provide any arbitrary 36v source, do you or anyone else make/sell such a thing?
E.g. for range extending a cargo bike I'd find the cost/weight ratio of a beefy ~1220 Wh AGM 12v car battery coupled with a boost converter much more appealing than something that emulates the form factor of a ~500 Wh Bosch battery with Li-Ion 18650 cells, the range more than makes up for the extra weight.
A. https://infinite-battery.com/pages/compatibility-guide-of-th...
Perhaps you can send us an email at contact@gouach.com with more details on your setup, so I can transfer it to the technical team?