Hey Bernhard,
The solutions aren’t optimal, yes. But, they’re the only solution for now.
Regarding the button, you placed it in the Footer. You should be adding it in the Header Bottom area. Please refer to my previous screenshot. The Header Bottom area is fixed at the bottom of the screen all the time so if you have a button in there, it will show at the bottom of the screen all the time. The only difference with that is the original Scroll Top feature is hidden initially. That cannot be replicated.
Regarding the sticky bars, I don’t see the issue you described. When I scroll down and back up, the content of the bars remains the same width.
What I see are blank areas when the bar sticks. Please disable the Sticky option of the empty bars.
Thanks.