Specs:
Studio One 5.2.1.64495 Trial
EZDrummer 2 (build 21073 64-bit AU) Trial
Mac Mini M1, Big Sur 11.4 (20F71)
I found, that EZD2's UI dramatically slows down Studio One. Check out the video:
No heavy apps were launched during the test. Lags appear periodically: 85% slow, 15% normal.
Not only EZDrummer's UI freezing, but S1's too. This issue make EZD2 totally unusable in S1.
This problem is not reproduced in other DAWS (Logic and Ableton tested), so I suppose, that problem is in Studio One.
P.S.
Not sure, if it's useful, but Superior Drummer Trial doesn't have this issue.