Some Pokémon have different catch rates across different versions of Gen 1, so that they hold different hold items when traded over to a Gen 2 game. Currently, one has to use the Batch Editor to edit catch rates, and setting the folder path to anywhere other than the save file seems to result in edits not being saved, making editing a .pk file(s) in a different directory seemingly impossible. I would therefore like to request an option to edit certain Pokémon's catch rates in one of the tabs in PKHeX, though limiting the options so that it displays legal results would be ideal. Here are the options for catch rates that I know:
Pikachu: 190 in Red/Blue, 163 for Yellow Starter
Kadabra: 100 in Red/Blue, 96 in Yellow
Dragonair: 45 in Red/Blue, 27 in Yellow
Psyduck: 190 in Red/Blue/Yellow, 168 for Stadium Amnesia Psyduck
Dragonite also has a catch rate of 9 in Yellow, but wild Dragonite cannot legally be found.