The time is now. I just uploaded a full 151 encounter patch! Still trying my damndest to get Meltan and the Alola forms into the wild, but it might not be possible with this game's bin structure. As far as I can tell, a single byte corresponds to the wild pokemon in a slot. Alola forms and Meltan have an index number well above 255.
I can't remember if it was you, but someone requested it and after I got the stuff ready to hex-edit my EXP reduction pack, it wasn't too hard to do it again with a lower value. Glad you appreciate it!
Unfortunately, I still have no idea how to add Meltan or Alola Forms to encounter tables. Their index number is above 255, which means they don't fit in a single byte and Let's Go appears to only have a single byte allocated to an encounter slot...
Uninstalling them is as easy as deleting the atmosphere/titles/010003F003A34000 and atmosphere/titles/0100187003A36000 folders from the SD card.
They only overwrite/overlap with mods that alter the same files: for example my encounter table mods will overwrite someone else's if you already have them on the SD.