I tried it again (after not using it for a loooooong lot of years, ok, maybe 1) and it is better than it was but still not worth using imo.
I set it to show 'most recent' in my feed. Recent is not random stuff I posted last month, followed by an hour old post followed by a day old post followed by a 15 minute old post. Setting it to 'top stories' made no difference...and no, what it was showing was not really 'top stories', just muddled crap.
If I hide a story then I don't want to see it, so don't put it on the app. Doesn't show on mobile.
It really isn't any faster than the mobile site on Chrome, except maybe loading photos.
I had no alerts/notifications set. Refresh rate set to never. HUGE amounts of RAM used when I wasn't using FB. Why? It's not set to do anything!
Unistalled. Again. For good.