[billpg]

One thing I would find useful in the situation is a shared IPv4 machine that will do host-based HTTP(S) proxying. This way, I can have an AAAA directly to my IPv6 and an A pointing towards the shared machine for those who can only do IPv4.

[canvayio]

A dual stack reverse proxy is already implemented and provides your domains with full IPv4 capabilities.

So even IPv4 only clients can reach your domains

[zrail]

I use fly.io for a similar use case. I have Nginx running in Fly and then use their baked in IPv6 Wireguard to connect backends.