You should add your DNS forwarder as its own node in Tailscale, and configure the tailnet to resolve DNS through it. That way you’ll be able to resolve both MagicDNS node names and your local domains, as well as being blocklist-enabled. Besides, I think you can also define custom A/AAAA records on your Tailscale console, skipping local records on Pi-hole altogether.

I’d also recommend Technitium for a new DNS solution, mainly because they’re going to add support for clustering soon. This could be highly useful if you want to configure blocklists once and sync them between different Technitium nodes. Should it works out, I’m thinking of installing it alongside every Tailscale exit node, for the benefit of synced blocklists, local domains, and exit-node geolocated IPs for external domains.