aerith revival injects scenes in your flevel. these scenes replace old scenes. window size is determined by code in your flevel scene which means ultima has designed the textboxes, most likely, without menu overhaul
Menu overhaul changes the font and makes text a lot less space hungry, which results in 'too big' textboxes
This is perfectly compatible it just doesn't look pretty.
The only way to fix this is to open your flevel with MR, load your window.bin under the settings and then manually resize every textbox that is 'broken'