A couple comments on the stickie header implementation:
1) Thank you for working on this, I find stickie headers useful particularly on long single-page designs.
2) One problem with this version is the header scrolls off the top, then when you reach the bottom of the header on scrolling, it abruptly reappears as a stickie header. This is jarring. If you only wanted one header and just make that stickie, then the initial header should NOT scroll, it should always be stickie.
3) In addition, one often wants the stickie header to have less height than the initial header. So you really need to design two headers, the initial, and the stickie one. Most themes that have stickie headers use some kind of fade transition between the initial and the stickie header. see examples of how Impreza theme does this at https://merrill.com/ or https://privatetrusteeservices.com/ and how Avada theme does it at https://betteconsulting.com/bette-kiernan/
You can see the problem here: https://stevenstraussmusic.com/product/along-the-navajo-trail/
(By the way, I’ve made Large Device and Medium and Small Device versions of this header as you suggested using the Responsive settings on the rows)