(quoted from post at 13:21:19 04/08/19)
(quoted from post at 21:07:39 04/07/19) though to be fair it appears the "resin system" you reference is either epoxy or acrylic. But its hybrid nature is a bit more complex than your hierarchy.
I didn't honestly find the original post super useful. It had a bunch of stuff that most of us will never see or be offered at a paint store...
PAINT:
Alkyd/synthetic < acrylic/lacquer < urethane < polyurethane
Something to note is that as the better it is, the more dangerous it is. Basically this list ranges from Rustoleum to Imron.
PRIMER:
This is more complicated because you have so many different use cases, but generally-
etch - Good for bare metal, old school, still used in body shops due to fast drying, rarely labeled to be topcoated so it needs some sort of seal coat over it before paint. Contains some level of acid.
epoxy - Best for bare metal, best sealer over urethane before topcoat, best sealer over etch before topcoat, some not compatible with acid containing products (treatments, etch primers). Very durable stuff and super adhesion on a proper surface.
urethane - Good for filling scratches/body work, not suitable for bare metal (although some are labeled as "DTM" this is rarely intended for a large surface), also good for sealer before top coat when thinned down, works over epoxy, etch, polyester.
polyester - Best for for filling scratches/body work especially when needing more fill. never top coat without sealing, often not compatible with etch primers. basically it is runny body filler
lacquer just stay away from anything that says lacquer for paint and primer. Doesn't really matter -- old 1K tech, likes to crack with age.
'enamel' primer (these are your 1k, non-build, bare metal primers) good for bare metal and a base for cheaper projects. not as durable as epoxy.
bare metal: enamel < etch < epoxy primers but etch comes with the caveat of needing another coat before topcoating
surfacers: toss up between urethane /polyester depending on what is needed. but polyester again comes with caveats of needing another coat before topcoating and is harder to sand/deal with
sealers: enamel/1k's < urethane < epoxy
There is no such thing as 1K epoxy.
Etch primers often contain chromates which are bad news for your health.
Polyester primers can be a pain to mix and work with, but are fantastic for filling.
As you can see epoxy primer and urethane primers are your most versatile and easier to work with in their respective uses. Unless you have some serious voids to fill, I wouldn't bother with polyester.
For some reason this forum has a real love affair now with metal treatments. I'm not sure why. You do not need a metal treatment for adhesion (it can work against you in fact) and 9/10 times you don't really even need it to get rid of existing rust. It has its place, but as far as being part of "standard practice" you are likely just wasting time and money with it.