I may have misunderstood the issue, but you can choose the DoH provider you want to use (Menu > Options > General > Network Seetings > Enable DNS over HTTPS > C

I may have misunderstood the issue, but you can choose the DoH provider you want to use (Menu > Options > General > Network Seetings > Enable DNS over HTTPS > Custom). Sure, a default has to be provided, but most of the people who will activate this option knows what they're doing, and which provider they want to use/avoid.