This is really great feedback - thanks!
I hope to get a patch build out asap with some fixes!
Have you tried the new PlayMakerControls component? It should be useful when you have multiple FSM components on a GameObject, allowing you to collapse the individual components. There is an editor cost as long as an inspector is open, but I'm looking into ways to minimize it.
More documentation for the new features is coming soon...
I did tried it, but I didn't find it useful for my workflow. I would love to collapse all those FSMs and get my performance back, but I need at least one edit button visible, cause I use playmaker in a locked state. I can even say that when I select game object with lots of FSMs I usually don't look for specific fsm in the inspector, I hit edit button on any fsm on that object and then look for FSM I need in this list. Cause it's faster.

So if PlayMakerControls was able to solve that issue, I would defiantly use it and it would greatly improve my workflow. And it doesn't need to do a lot.
A solution that comes to mind is to have drop down list with all fsms in this game object in PlayMakerControls and once you select a fsm from that list it will open it in Playmaker.
If this will be implemented, then I would love to see editor option that will allow to automatically add PlayMakerControls component to any game object where I create FSM, if there isn't one already there, cause I would want to use it everywhere to be able to never "uncollapse" FSM components.
You can click the FSM name in PlayMakerControls to open it in the main editor.
There is a new FSM Controls window that works the same as PlayMakerControls (without the component). It has an option to add the PlayMakerControls component to the selected GameObject. Not sure if that helps with your workflow...