[rollcat]

You're much more likely to be already using 10/8 as a part of your setup, whereas 100.64/10 has only really been a thing for residential/mobile ISPs. (I have no idea what happens to Tailscale when your carrier gives you a 100.64/10.)

[samcat116]

Typically that CGNAT IP would just sit on the WAN port of your router. So in theory none of your LAN devices would hit that IP anyway (the router would be NATing everything). Your clients having a route to 100.64/10 pointing to the tailscale VPN interface shouldn't have an issue (unless you install Tailscale on your actual router, that would take some special setup).