When all data from JPL are downloaded (or displayed from the cache), you can choose which parameter you want to change, but you can't enter any values. Upon trying the AP no longer corresponds and turns grey or white. It doesn't crash, but when returned to speaking terms nothing has changed.

Fixed. (a) If no magnitude info is available (e.g. JPL COMET) then related display restrictions are removed. (b) A single click will allow editing of the display restriction numeric fields.
Bonus: There's now a "In FoV at current date/time" display restriction that will restrict display to those objects that fall into the current FoV and the current local date/time.