Does Tailscale support opportunistic use so that other people running Tailscale will transparently use it when they connect to you? Also, "Today, Tailscale's W

Does Tailscale support opportunistic use so that other people running Tailscale will transparently use it when they connect to you? Also, "Today, Tailscale's WireGuard implementation is not post-quantum secure" (from https://tailscale.com/kb/1460/post-quantum-cryptography https://tailscale.com/kb/1460/post-quantum-cryptography)