https://www.mtm2.com/~mtmg/misc/Beta0.50hotfix1.zip
So far the issues that have been worked on/fixed are the ones mentioned on page 1 (up to where Cale says his textures are low quality). I haven't looked into fixing things past that.
Also I haven't fixed the Heights water issue yet because I cannot get MTM2 to run on my steam deck and I have very little patience for dealing with consoles (if you ask me, consoles should all be burned to hell). Like... my patience is so little that if PCs did not exist I probably would have never played video games.
As far as the menu, if you go through every single screen (and make sure you open everything, like edit opponents, edit favourite opponents etc), then press F6 (remember, after you opened every screen, this includes the pause menu during a race), the game will dump a menu_layout.txt file right next to monster exe. Now go into windowed mode in MTM2, open the .txt file and start editing those numbers. Every time you press F5 in the game, it will reload the .txt file so you can do a somewhat of a live edit of the menu. Just make sure you save a back up of the file whenever you do an edit. If you accidentally press F6 again, it will overrite the file together with whatever changes you made.
Likewise, in the MTM2 folder you can make a MenuArt subfolder and in there place all the .BMP files you want to change the backgrounds. Just make sure you take a look at the file names in the UI. Just replicate those names. If you just replicate it saves it universally. If you add a 1440 or 1080 or 480 at the end, it will use that image for those resolutions specifically.
The order of priority is MenuArt, then it searches in .POD file for both a MenuArt\file.bmp or UI/file.bmp