I have a tile map that looks at the average value of X in each region. At certain zooms there are only 1-2 users, so the average doesn't mean much. Is it possible to add a filter that removes tiles for regions that have less than n users?
I don't think so. You could try to use "Scaled circle markers" in Options so that the data points that have less users associated with them are visibly smaller -- perhaps that would help.