I went looking into how that works, and, apparently, tailscale adds individual node routes (in table 52). So yeah, you have very low chances of getting into trouble even if you have an interface with 100.64/10.

Yeah, you’re absolutely correct. I misread that thinking OP would have the CG NAT endpoint and taikscsle on the same physical device, which, I still think, would be a problem: you’d have two interfaces for 100.64.0.0/10. But if CG NAT terminates on the modem and you run taikscale on devices connected to it them there’s surely no issue at all.

I’m actually not sure you can easily get tailscale up and running om such as a setup as it uses the same cgnat ip range.