That’s what I did:

• There is *.selfhosting.domain.tld that points to my router’s IP address, which then redirects to an nginx+certbot reverse proxy
• Then there is *.local.domain.tld that points to my local IP with Caddy

The only challenging part was to configure Caddy to issue SSL certificates using the DNS challenge since *.local.domain.tld isn’t exposed to the outside world.