It depends, are there salient bugs that stop use of the program?
Why do programs have to be maintained forever? Why can't we just call things "done" now and then
The developer could call this out clearly if it was his plan. Tho the tool itself is a good start but the lack of export to usefull formats makes it kinda only partly usefull since you will have to write a converter to target format from his specific format. I did so for godot but was quite a pain and rn im considering writing a tool myself that directly exports to such a format instead of havin a secondary format inbetween that i have to interpret and convert to the target. But ye i gave up on it anyway long time ago