Can I use Tailscale and WireGuard client together?
Yes, but not recommended to turn on “Custom Exit Nodes”, I don’t know what’s gonna happen.
That said, enabling both Tailscale and wireguard client make traffic complicated.
Before firmware 4.5, the underlying traffic of Tailscale(port 41641) goes via Non-VPN interface.
From 4.5, it will go via wireguard VPN interface, so you will find a public VPN IP at tailscale console - Machine Details page.