The transition timeline works just how I want it going into the magnet region, but then each time the magnet region loops, it replays the transition timeline which I do not want.
Is there a way around this other than just using a sustain point, away from the transition region?
Magnet regions don’t loop. They seem like they loop, but what’s actually happening is that when the playback position reaches the end of the magnet region, it keeps going. However, because this results in the playback position being outside of an active magnet region, it is immediately pulled to that magnet region - and, as is always the case when the playback position is pulled to a magnet region, it passes through that magnet region’s transition timeline.
If you don’t want the playback position to leave the magnet regions and then be pulled back into it via its transition timeline, you need to prevent it from leaving the magnet region. The easiest way to do this is to add a loop region that starts and ends at the same timeline positions as the magnet region, but on a higher logic track. (Placing it on a higher logic track than the magnet region will ensure it takes priority.)