It isn't expected. But I have noticed the issue as well, and I'm looking to fix. I think it may have to do with how note lengths from beats are being calculated.
The Handel interpreter uses Tone.js for scheduling and playing notes. But because there is only one Tone.Transport per page, changing the bpm of the Transport would change it for all tracks.
So instead of using Tone.js for setting bpms, the note lengths are calculated based on the bpm and amount of beats, and scheduled in seconds. Which could lead to greater imprecision over time
The Handel interpreter uses Tone.js for scheduling and playing notes. But because there is only one Tone.Transport per page, changing the bpm of the Transport would change it for all tracks.
So instead of using Tone.js for setting bpms, the note lengths are calculated based on the bpm and amount of beats, and scheduled in seconds. Which could lead to greater imprecision over time