In order to properly move or copy regions -- specifically if the region begins or ends with linear tempo segments, or is moved/copied into a linear segment -- two points should be inserted at each edge point to preserve tempo envelope inside and outside region
REAPER can
understand and use multiple tempo markers at the same time point, but the native actions for moving or copying Regions do not utilize this feature, resulting in changes in the tempo map inside and outside the Region:
As a demonstration that the tempo envelope can be properly preserved when moving or copying regions -- even when copying into a linear segment -- here is my own "Insert empty beats" script doing something similar:
