But setting up the 2nd or 3rd depends on each person’s screen resolution.
True, but without having the option in the plugin, it’s the best alternative I’m afraid. I’m sorry, I don’t have anything better to offer at the moment.
As for changing the top space from pixels to percentage (to see if that works): I’d need to do some tests with that, not sure if it would work right out of the box, because the position of the sticky element is calculated by taking the original position (in pixels) minus the top space (in pixels) minus the amount scrolled (in pixels)….so replacing one of them to percentages might not be ideal. And, to be fairly honest, I’m not really sure if that would solve your issue actually.
I wish I could be of more help, but it would take a bit of work to make it work for your site, since it’s not directly a functionality that matches the current functionality of the plugin. I hope you understand.