Is there a way to, with ONE click, choose a Layout and it automatically uses results from a collection?
I find myself switching layout a lot, and would love to not have to do it in three steps.
(Choose collection, Show in editor, Choose Layout)
With Scrivener all by itself, no unfortunately! Layouts are something you can apply to any project at all, and as such they are devoid of any details that would require one specific project for them to function correctly.
Something to consider though is putting some shortcuts on your frequently used layouts. I have a few that I switch between frequently, and they are all stuck to the F1 key with various modifiers.
And with pure macOS+Scrivener stuff out of the way, two words: Keyboard Maestro. When the question is: can I do these three completely different things with one button, KM almost always makes that answer: yes.
Another option in your case, since this doesn’t require anything super fancy (like detecting the presence of a checkbox on your screen and clicking it for you), is BetterTouchTool. Really you’re just chaining three different menu commands together here, and that’s something that tool can easily do as well, and it is a lot more economic (around $20 for a lifetime license, or $10 for one that grants access to upgrades for two years, without actually expiring).