I can't currently think of other elements that would be having such an impact on repository page load times.
There aren't any further workarounds I can think of either that will help, short of making a change in the code.
You could try commenting out the following line, to see if preventing the widget from loading will help resolve the issue:
One of our developers also said:
You could also stick a bare return; at the top of https://github.com/artefactual/atom/blob/qa/2.x/apps/qubit/modules/repository/actions/uploadLimitComponent.class.php#L23
Remember to clear the application cache and restart PHP-FPM before testing again. I would also recommend clearing your web browser cache as well.
As I mentioned, there should be a setting included in the 2.7 release to disable this without having to make local code modifications.