I tried setting my background fps to 21 and quested for a while on some lowbies with the watcher on, and after a while I ended up having to manually click for quests in all the windows pretty often since the communications channel was too clogged.
Definitely going to keep the watcher disabled until this is fixed, really nice when it works though, but I still hate being unable to click anything behind it, especially since it prevents clicks for its full size regardless of how many quests are actually being tracked.