I've been to FOSDEM since around 2011. My advice to you is to not try to over optimize your schedule and the tracks you want to attend.
Overall the format of 1h makes for rather lightweight presentations, nothing really goes in depth, so watching the videos is good enough.
You should rather see it as a way to have social interactions with the maintainers of libraries you like, go to dev rooms, hangout in the cafeteria, have a good time with nerd friends, etc.
In general, I find conference presentations are useful in a "This is interesting. I should dig into more." sort of way. I actually favor shorter presentations for the most part.
I agree more broadly. Trying to flit from room to room at FOSDEM is an exercise in frustration. I usually hang out in a devroom that has people/content I'm interested in, get together with people, etc.
So much is on video these days that there's less reason than ever to attend an event for breakout presentations.
Overall the format of 1h makes for rather lightweight presentations, nothing really goes in depth, so watching the videos is good enough.
You should rather see it as a way to have social interactions with the maintainers of libraries you like, go to dev rooms, hangout in the cafeteria, have a good time with nerd friends, etc.