I was really bothered by this, and decided to make a place to store all my files, neatly categorized. Eventually I got bored with shifting/archiving manually that I make a neat bash script that asks for a few details and moves the files for me to a predetermined location. Having two siblings much less incompetent than me doesn't help. If you want, I could make a simplified version of that script if you want. Otherwise, I'd just copy my MarbleBlast folder out and put it into its old named folder so that you know how to find it. It would've been more helpful if mod makers changed the usermods directory for their game so that this would be unnecessary.
For the side question: it is indeed possible.
First, you would have to rename your old "platinum" folder in the Library's MarbleBlast folder, to "platinumbeta".
Then, you would have to rename every single "highScoresplatinum" with "highScoresplatinumbeta" in client/mbpPrefs.cs, and save. BACKUP your file first! MarbleBlast will wipe the file if there are syntax errors. You can simply open it in TextEdit and do a find/replace.
Thirdly, you'd also want to replace "easterEggplatinum" with "easterEggplatinumbeta". I'm not 100% sure if it's still used in MBP 1.50, for I haven't seen it in my 1.50 prefs file, but I'd do it anyways. Save.
Fourth is to backup the config.cs file. Delete the original. If you don't, there may be some missing keybindings. I couldn't rebind "t" to chat, either.
Fifth step is to launch MBP 1.50. Then close. You could also log into LBs if you wanted to. (This is all assuming you haven't already done this.)
Sixth is to either remap your key controls in the game, or close it and manually replace the new settings with the old ones. Changing it in the game is recommended.
I feel like I've forgotten something, but that seems to be it! Keep in mind that your data/times always have and will remain offline.
Hope this helps, or at least somewhat!
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