Hey @AshEaria!
It’s not possible to install a specific hotfix from the Epic Launcher.
Though would you mind expanding on this part:
Upgrading the engine version of your project can indeed produce unexpected results, therefore is generally not recommended to do mid-development. However, those you mention are hotfixes and not entirely different engine versions. All they do is fixing bugs and improving performance. You shouldn’t encounter any issues after upgrading your project to the latest hotfix of the engine version of your choice. I personally never experienced such a thing, nor saw any reports of it online.
Still, to be safe, you can try upgrading a copy of your project on another computer and see how it goes if you like.
Hope this helps! 