The values in "gallery.gd" are default values and are only used when a new "progressdata" file is created in Strive's AppData. Otherwise, they get overwritten by the values in "progressdata". The simple way to reset those values to your new default is to delete "progressdata".
The more complex way would be to open "globals.gd" and change line line 198: "if temp.has(character):" to "if false && temp.has(character):" by adding the " false && ". Then save a progress once to overwrite the saved values with your default values, and remove the added code. This way is probably unnecessary, but it would preserve any save file summaries(the data about a save you see when you select it in save/load menu) stored in "progressdata".