This is probably a terrible idea that I personally wouldn't like to encounter, but might be profitable..... What about a one-time payment for the editor and another payment everytime someone builds a production-level game? (i.e. there is a "test" build mode that has watermarks and other limitations)
Its just an idea. I, personally, am fine with a subscription because, as much as I hate them, I am already paying some (Amazon, my internet, my garbage pickup, various memberships) and this really wouldn't be too painful for me.
I understand the existing userbase hates this idea (as they are used to the one-time payment); however, (and this also sounds terrible) you will be able to attract a new userbase.
I don't agree with what other people are saying that "no one knows about ultra engine" or that "everyone will be focused on Godot." I found ultra engine years ago, and that was because I really hated what was available. I loved Leadwerks, it was intuitive, etc. Adding "performance" and "good graphics" as main themes of Ultra will definitely provide you with a customer base as I cannot count how many times I have searched "performant game engine" and not received a good answer.
I, once again personally, hate Godot. I absolutely abhore it. My brother loves it (he's a foss "nut"). Although he hasnt actually produced anything with it successfully.
The main turnoff for me for any application is UI. If I don't like the UI, I won't use it. Godot tried to be unique, instead of just doing what works. Their interface disgusts me. So despite all the pros Godot offers, you won't see me using it. I'm fine with Leadwerks/Ultra.