Create a Collapse All Layers Button
Currently you can collapse (or expand) all sub containers by Alt key clicking on the little arrowheads on the left-hand side of the top level container items. It would be great if we had a button we could click that collapses (or expands) everything.
Bonus points if this could be called by an action or script!

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L Coyle commented
Please make this a reality. We shouldn't have to click click click click click to just collapse everything.
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Christopher Page commented
I can't believe this is STILL not a thing. I'm positive there used to be a cheat, or some third party extension that would allow you to do this, but damned if I can find it now
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Another bonus point for having an assignable hotkey for that :)
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Francis commented
This is just simple common sense.