Hi Max, regarding layers? Can we maybe split this topic?
It happens with just a new file. There are many posts in the forum regarding layer interface being slow.
Specifically if you create sublayers of about 3 levels deep, and then start adding layers in that sublayer level, you can notice a big lag, as I can click 10 times, and stop clicking, and Rhino will continue adding layers after I have stopped clicking.
I have added a post in this thread: