No place around me to install mini-splits for cheap so I just got the EPA 'licensing' and did it myself. As long as you don't offer the service commercially, in most states, I think that's all they need.
These systems were designed so that people with a basic education in third world countries can install them. It's not rocket science.
The universal is proctored, so you have to have the *FCs and limits somewhat memorized, it's definitely just rote memorization and if you have exceptional memory you might just remember it all the first time without any 'study'. A person like me with relatively average intelligence would probably take a couple days, but it's definitely a lot better than needing 4 years of HVAC apprenticeship or something.
Technically you need part 2 or universal to do most home HVAC systems, but part 1 (or even an EPA 609 probably) would get you the refrigerants, so it's largely a moot point.