Quick update to let you know that further testing resulted in some tweaks (will update main post soon) and that sadly email and anything needing different ports still does not work even through the magic of Tailscale 😕
TL;DR: Yes, you absolutely can run Cloudron through Tailscale (and plain-ol Wireguard too); No, it's not perfect and things that need different ports to 443 will likely not work without additional iptables tweaks if at all