Hello! Thanks a lot, I really appreciate your feedback and ideas here.
I'm uncertain about moving it to SDL2 and fixing it up before starting the redesign because it seems like it might take too much time to pull off. I appreciate that some users like what they currently have, but some users also aren't able to effectively use what they have, and improvements are generally good. I think it being an early access / indev product means that you're not only buying what it is now, but also its potential.
While it is certainly true that I can't please everybody, ideally, nobody should be upset with MasterPlan a year from now in comparison to it as it stands today. If I kept one version back, people would have to choose, and I might have to end up supporting effectively two codebases because of security vulnerabilities, feature requests, etc. It seems wisest to put my energy into trying to cover all my bases with the design update, and try to keep everybody happy with the result moving forward.
Thank you for your feedback, again!