There are a few options there.
As someone else mentioned if you’re using IPv6 then it doesn’t matter, you’re already routing internally even if you’re using the public DNS name, no extra work required.
All the rest are for IPv4.
If you’re not behind CGNAT some routers/gateways are also smart enough with their routing to recognise when they need to route back to their own external IP and will loop back locally instead of making any hops out to the internet. Again, if this is the case for you then no additional work is required other than perhaps running a traceroute to confirm.
Another option is to add a local DNS entry for the name you’re using to resolve to a local IP address instead of your public address. The complexity (or even possibility) of this is going to vary considerably with your setup. If you’re running your own local DNS e.g. pihole or similar then it’s trivial. This is how mine is set up.
If all your clients are going to be on PCs (or devices you have more than the typical manufacturer allowed modicum of control over) then you can do something kind of like the previous, just with all your local hosts files.
If none of the above are options, then you’ll unfortunately have to fall back on using a local name/address, which means a slightly different client setup for devices you use exclusively in your home versus ones you might use elsewhere.
Exactly this. I have a couple of small projects that are MIT licensed specifically because I don’t care how people use them or what they use them for. If someone finds it useful then they’re welcome to do whatever they want with it.
This idea that I’m being somehow hoodwinked or taken advantage of because the thing that I explicitly said could be used freely is being used in a way that doesn’t align with the values of some other completely uninvolved third party is beyond absurd.