How many is many? If possible attach your override language file found below and will see if I can reproduce the performance loss.

/components/com_comprofiler/plugin/language/LANGUAGE/override.php

Our repeat usage is kinda heavy but latest CB releases have significantly improved its performance. Please be sure you've latest CB build installed.

I'll be honest it was never designed to handle such a large usecase. You should just flat out have a custom language plugin for so many overrides. At any rate I am seeing a slow down, not 3 minutes or anything of the sort, but it's definitely slower than desired. Will see if there's a way to improve it further, but even if improved you're likely to hit input limits as it's 2 inputs per override meaning you'd hit 4000 inputs and may need to adjust php.ini to allow for more.

forge.joomlapolis.com/issues/7024

Looked into this further and I don't have anything to suggest beyond directly edit the override.php file as you've far too many overrides than was intended for this usage so it can't handle it. Have noted the issues in the ticket and will likely require a rewrite to our overrides usage to handle larger sets of overrides, but it seams like you're trying to use overrides to replace the need for a language plugin and instead should just install the necessary language plugin.