Steps to reproduce the issue

My site (thanks to Overload) is huge.

I (could) have 20,000 different Authors.
I (could) have 20,000 different Categories.

The actual number is irrelevant.

The point is that a menu item pointing to Smart Search will load ALL the author names into the HTML and all the Category names into the HTML

The Problem:
This makes the browser unresponsive, or makes the selection of a single author or category a slow huge task. The browser struggles to load the elements when clicked

They are all loaded on page load into the HTML regardless of if advanced search is being used.

Expected result

Great user experience on large Joomla sites.

Actual result

Bad user experience on large Joomla sites.
This makes the browser unresponsive, or makes the selection of a single author or category a huge task.

System information (as much as possible)

Am I being unrealistic with 20,000 authors? maybe, but the same applies to 100 & 10000. Joomla should still be able to perform and not grind the browser to a halt.

Additional comments

Here is a dump of a HUGE database for you https://www.phil-taylor.com/HUGE.sql.gz (Joomla admin u: admin p: adminadminadmin)