As a PSA, mini splits are pretty easy to self-install, and it can save you a bundle, even when buying all the equipment new. Lots of youtube videos on how to do it, though I'd add that most of them show using a manifold with analog gauges to do a vacuum test. You should really get a digital micron gauge and pull a deep vacuum.
Good point, though you generally don’t really have to handle coolant for mini splits, they come precharged. You mainly have to add more if you have a longer lineset.
I’ve heard the online EPA course/test for coolant cert is pretty easy, though.
The main thing is just making sure you test the lineset well, including deep vacuum decay, and ideally a nitrogen high pressure test.
