Thanks for the files, stevehuon, and for using Dropbox.
The problem is caused by the setup, creating every single clone newly.
I understand that you like to have an instant response while adjusting the scene. If that is correct, then have a look here:
https://www.amazon.com/clouddrive/share/Z7F92OqZpyZbgzroCE0MELIxbdlAunfy8opUp9DEDOs
I have set up a MoGraph selection that allows showing on every 12th clone. Switch off the Plain Effector> Hide Selection, and all clones are visible.
Hopefully, that helps your system. Perhaps you can place even a lower number into the Formula. See image.
Enjoy your weekend