The most concerning part about Rustdesk is that they delete issues that question the source of the software or Rustdesk’s potential to be influenced by the CPP.
Seriously, if you make the effort to create a big piece of software and then you open source it and then someone opens a ticket in GitHub asking you those questions, how would you feel?
Because neither “what is the source of the software” nor “potential influence by the CPP” has anything to do with the software itself.
You are free to conduct a security audit of the project and based on the results you can open this thread but saying that they have deleted issues opened on their GitHub page that have nothing to do with the software itself is a pure form of witch hunt and I am genuinely surprised how many people have agreed with you.
You should also consider the time you will spend configuring and setting up everything in Incus.
If you do this with educational purpose go for it, otherwise I will advise you not to, as Proxmox has a wider support and probably finding information, etc. for it is going to be easier.
Alternatively, why don’t you dedicate one of the hosts to Incus and play around with it and decide if it works for you or not.