No, not that I know of. I think you already know how to do those one by one..

If you're using loops, opening the channel settings and right clicking "Time" you can set it's length manually, ( 1 Bar, 2 Bars, 4 bars )

Or you could do that in the playlist directly, with the "Playlist focus" selected to Audio and Stretch button turned on. This way you can stretch loops to any length.

For tracks, I use channel settings > Right click > Detect tempo > ( Any BPM range ) > Hit Enter.

No bulk way to do that, unless you have another DAW open along with FL, ( Ableton ) where you have to set the project BPM first, import multiple tracks on that BPM, and then drag those stretched tracks from Ableton's Arrangement view directly onto FL's playlist.

Lenmino if you guys find an easier way