why not have a report that only instance mods can see? discord may be too much for some.

if in your instance there are instance moderators and the instance becomes crowded, you and your mods may not hear everything nor see everything, plus vote kicking is hard to start.

when an user sees someone suspicious they can do an instance report, add a description, maybe a picture too, and send the notification to all the moderators in the instance, then a moderator can take action, and once it is solved they can set the report as solved.