I love the idea of this mod, excellent especially for SE. I've discovered though that since I installed it, it causes my alerts in the bottom right to not appear as expected, with numbers jumping around wildly and entities flickering on and off really quickly (much faster than the normal Factorio flicker when you're over the 600 entities)...is this normal behavior? Any thoughts here?

Unfortunately yes, this is "normal" behaviour.
Due to the way the modding api works the performance of this mod is heavily dependent on the number of visible alerts. So by default all alerts are deleted as soon as possible, after two ticks, which causes the flickering. The number of ticks is configurable in the mod settings, if your pc can handle it you can increase the number of ticks there.
Of course this only happens when at least one scanner is present, removing all scanners is also a (quite useless) option.
It may also be possible to create custom alerts mimicking the default behaviour, but I have not looked into that yet.