That’s true, if tempo/meter isn’t served by an external clock, one must set them for each song state. I’ve found that to be very quick (adds another few seconds per song prep time).
I think you can set each song state to auto-open a particular rack when the state loads (e.g., using a binding). Like you, my VST controls are not consistent so I need notes, but I personally prefer forScore for my sheet music, in which I have notes about which buttons to press when; so I only refer to my rack comments when prepping. I’m also loving my Presonus Atom SQ controller because it lets me color-code the buttons per song, which really helps me remember which is which. (See my other thread on the merits of that controller.)