Hmm yeah I was actually also just pointing IP's for a good while[0] until my mobile ISP (4G router) decided to not allow custom DNS to be used, after which I installed the NextDNS app (with DoH or whatever is default) and got rid of that restriction.

[0] I remember I had a cronjob calling a particular custom NextDNS URL regularly, through which I'd like to remember I was able to choose a specific profile