Here is some javascript that I've used to freeze my header rows when scrolling down.  You may use it/modify it for a future update if you like it.

var table = document.querySelector('table');

if (table != null )    
window.addEventListener('scroll', function(){
var top = table.getBoundingClientRect().top;

    top = document.body.className.search('admin') > 0 ? top - 32 : top;

if (top < 0 )
table.querySelector('thead').style.transform = 'translateY( '+ (-top) +'px )';
    else 
table.querySelector('thead').style.transform = 'translateY( 0px )';

    table.querySelector('thead').style.background = '#fff';
});