SR 5th ed. Advice/Instruction sought with editor

[Seeker1728]

I've created a few custom mentor spirits to round out the rather spartan selection that 5E has available. While I've had no trouble adding their advantages from the tables provided, adding customized disadvantages are proving to be a issue.

I've wanted to create my own disadvantages for the mentor spirits I created, which I figured I could add in via the "Mentor Spirit Power" tab, since that's where the canon spirits have their disadvantages listed. But after entering the flavor text and checking the desired resistance stats the custom disadvantage does not appear in the same table as the canon disadvantages do.

Typically my editing efforts are done by comparing existing content, studying it, and then in a sense reverse engineering to my end goal. But I'm stumped on this and even after studying the author kit pdf I haven't been able to suss out how to add my custom content to the prepackaged content of the mentor spirit disadvantage table. (hope I explained that well enough )

A secondary question is, should I make it a habit to always go into the "Sources" field and check the "user content" box? Or should I generally not worry about that?