Does the job

This did a great job reducing useless requests and code for emojis, loading dashicons for non-admin users and things like that. It’s a simple install and, as mentioned, it is a free and open source plugin that competes nicely with some paid plugins.

If you just want to get rid of emojis, try Autoptimize (the Extra settings) or Ryan Hellyer’s Disable Emojis plugin, but you’re still going to have all the other stuff this gets rid of.

If you want to pay money, you can match this and maybe get rid of a bit more cruft with the perfmatters Premium plugin ($25/yr).

In my experience, it’s pretty common for an optimization plugin to cause a 500 error. There are a lot of little things that can go wrong and if you are trying to push performance by doing things the platform (WordPress) is not designed to do (in fact is designed NOT to do), you have to be ready for some collateral damage.

In my case, this plugin worked flawlessly, but I would recommend that any plugin like this be tested on a staging platform first and then deployed to a live site.