This suggestion is a quality-of-life feature that would add 2 features in the settings menu, one easier to implement than the other: a button that saves your current settings across all your other files on the same account, and another button which saves your current settings as the new default settings.
The first one is quite self-explanatory: in the settings menu, besides the apply button, there will be another button to save across files, which will change the settings in your other files to match the current settings you have on the file you have saved. This won’t change settings that cannot be changed due to unique circumstances, such as the player teleport settings if the file is a renown leaderboard file.
The second one is another button to save your current settings as the default settings. This is mainly for starting new files so you don’t have to change their settings each time you start a new one.