It's a little hard to do with one hand, but on Mac it is shift+option+cmd+e.

That is an adventurous key command... I hope there's an opportunity to reconsider that or get further feedback on it. I bring this up because I'm quickly finding myself wanting to toggle between that functionality as I create patches and test things out.

It is hand crampy for me...why not control+command+e or shift+command+e?

I completely agree @Jonah. I'm finding that I use the feature less IF the key command is less accessible.

Hello,

With this, thank to 11olsen, http://www.11olsen.de/code/max-objects/11strokes

You can load keystrokes in Max, so it may be possible to program your " shift+option+cmd+e " and to load it with a [bang] mapped with the key you want..

EDIT;..with good link..