Thank you so much for the tool! It's pretty amazing.
If you want some ideas for improvements: I think the UI still feels a bit yanky. Maybe the lines etc. could be slightly thinner and not take so much space.
And whats the reason for the 1024 x 1024 maximum? This makes the tool pretty unusable for many jobs.
Is it a performance / crash thing? Maybe you could make 4k the maximum? If it's prone to crashes, maybe only when an "experimental" mode is enabled or something?