Basic and Advanced Search page slowness because of huge number of records in multi-select dropdown

In Cases module, I had assigned users in multi-select drop-down.
On case search page there are 4000 assigned users loading in this multi-select drop down.
Because of huge number of users, this page takes more time for loading.

Is there any solution to increase performance to this page?

How to apply lazy loading for multi-select dropdown on search page? if anybody having solution then please share an example.

There is always a faster way to do thingsā€¦ Try this plugin, If you need demo, let me know!

https://store.outrightcrm.com/product/suitecrm-global-hide-manager/