Since I didn’t mention this in our other interactions—welcome to the community!
1/2. The setup your using is going to make this a bit difficult as you’re triggering the “sticky” pretty close to where the shrink/grow would be occurring—so I’d suggest you instead adjust your layout a bit so the Hero section contains the title and the sticky menu sits just below it (instead of above).
This will allow you to trigger the shrink/grow interaction based on the Hero section scrolling in/out of view and as long as you’re using the same class this should make it easy to reuse the interaction on any of your pages across all necessary breakpoints.
I recorded a quick video to illustrate the changes and how the setup would look for the interaction: