In > Prefs > Opus Start > Auto Start you can set to save open listers every N minutes, which means you have a one minute minimum. That's maybe the closest you can get using automatic modes. But you can avoid menue diving, if you use something like
Set SAVEFORMAT=folder,replace
and, for example, use the Background Events function (> File Display > Mouse > Background Events) for the quickest way to save your folder options, 'one click' style.
If, for example your MMB (middle mouse button) is still free, you could use that one. Just paste in that command into the MMB field. Or use some hotkey combination. As for the thumbnails thing happening, you must have your format lock being engaged in your automatic settings, somehow.
If you're happy with that one click solution, you can just remove the automatic format in the settings and start using this solution.
1st If I enter a folder and put thumbnails and leave it, all other folders will also be thumbnails.
2nd if I put a thumbnail in a folder and leave it and in the next folder I disable thumbnail when I go back to the folder where I had put thumbnail it is no longer in thumbnail.