If you came away knowing not to vent, to use the right refrigerant, not to vent, to take your waste to the reclaimer, not to vent, to leak test with nitrogen, not to vent, and that you can be fined $43,000/day for not having your paperwork in order… then it worked enough.
There are no standards on how many pieces of thin walled pipe a vechicle can use. It's usually a spiders nest of hoses.
You need to change you blower motor, or do anything that involves the dash, radiator, you are taking a calculated risk. Most mechanics might have a recovery system, but it's usually in the corner of the shop covered in dust.
It might help if the federal government standardized parts for the AC system?
I'm very careful, but the last time I changed my blower I borrowed a recovery system, but still made a mistake, and released all the gas. I was going to recharge it, but the generic evaporator core outlet to an ac line was 1" short. I had to go genetic because I couldn't find OEM.
And no don't make a mechanic's life harder with a bunch of regulations. They are already over regulated, and it's a hard job.
It can not be too onerous, because people need the work, and people capable of solving systems of differential equations have better opportunities than work on them.
A little repetition is good for the monkey brain.
I don't think that's what the drills are for. You do drills so that everyone is familiar with an organized process of exiting the structure, so that an evacuation can occur quickly.
In the absence of drills, everyone will still know where the exits are, but they'll form giant traffic jams that block people from using the exits.
So the EPA cert by itself isn't usually enough to work professionally (unless your repairing home refrigerators).