I could, but I'd rather not enable HTTP on devices that don't need it.

Don't get me wrong, I'm keenly aware there's easier ways to accomplish such a goal, but that's not the point. I have discovered something new and, as a way of practicing multiple other skills at the same time, am musing over homelab projects I could do to put it into practice and cement that knowledge.

It's just like my internal-only emoji DNS resolver: goofy, amusing, and ultimately impractical outside of the homelab, but still a great way to learn several new things together.

you could run ur own resolver somewhere and have ur devices update that? i think dns updates are a bit 'slow' sometimes so unsure how much u'd need to update them. if its frequent id say ur own dns resolver would be fastest as ur control the records directly on the box u query

Oh, well, writing your own dynamic DNS system is certainly a great learning project.