All of this is because of how I started this journey in the OMV4 days with that pair of Nextcloud videos by TechnoDadLife. That is how he set up the conf files. I am just now getting my head around the wildcard method and sub.subdomains. That and KM0201 ’s posts above have me itching to try a paid domain without duckdns. As you say, with the wildcard method there is no limit to the number of sub.subdomains. I didn’t take your post as “the right way” or “my way” at all. I enjoy seeing the different approaches. They make me think. In fact I do think you guys have a superior way of subdomain layout so that you have one domain preceded with nextcloud. airsonic. ubooquity. Navidrome. etc.
If you don't use a generic top level domain (.com, .net, .org, and so on..) and you do don't pay for all their extras.. they are quite cheap. I got mine through domain.com. I used .xyz for the top level ( "mydomain.xyz").. and after declining all the stuff they try to upsell you (whois guard, SSL encryption, storage to host the website, and lots of other stuff), it was $3 for a year. If you don't pay attention you'll have about $100 in your cart when you go to check out. Delete all that and just get your domain for 1yr... and it's almost nothing to try if it's something that interests you.