Describe your issue or idea
When I upgraded a site from Drupal 6 to Backdrop CMS, I noticed front-end pages getting sluggish, while the back end stayed quick and snappy. When removing the menu block, the front-end of my site was also quick and snappy.
After much further digging (thanks the devel query log!) I have tracked the problem down to the function menu_tree_check_access()
which adds an additional 1141 database queries to my page.
It's true - my menu tree is quite large. I still think there's something we could do to speed this up. I don't see why these queries need to be run uniquely for every visitor on every page of my site - when the links are the same on every page.
Recent comments
If you are talking about the progress bar shown by batch processes (for example, the one shown when you update your site), that seems to be themed by theme_progress_bar() and the css is defined...
How to change the width of the progress bar
In case anybody comes back to this, I think I found the problem. The dropdowns disappear only on pages that do not have any images in the image gallery field. That's because mosaic_grid's JS was...
Vanishing dropdown in primary navigation
Some themes have a dedicated spot in the settings that you can add a few bits of custom CSS for the element you want or you could use CSS Injector I'm not sure which progress bar you mean...
How to change the width of the progress bar