The applets window in the ARTIQ dashboard works well with applets saved in artiq.applets. In order to add custom applets in the dashboard, do the users need to create a fork of ARTIQ and add files under artiq.applets? I think another solution could be an argument (of artiq_dashboard?) linking to a folder that saves all the custom applets.
Expanding a bit on this question and https://forum.m-labs.hk/d/199-how-do-users-choose-folder-to-save-data-in, does ARTIQ encourage non-developer users to fork ARTIQ and make user-dependent changes or to use the vanilla ARTIQ (with documented options that allow users to do what they wish to do). It seems better to me to have options that expand upon the vanilla ARTIQ, so it would be easier to trace if a bug happens, and it would be easier to resolve conflicts if a user wants to update their ARTIQ to the latest versions.