Sounds like we've got quite similar MO's in our grow practices. Lol.I've looked at the transplant bags and they're really neat. For me they just aren't needed. I tend to keep my plants in the nursery pots until they've comically outgrown them then move them I to their final home these days. But if I was doing fewer larger plants I could definitely see the appeal. Once you get past about half gallon size getting the plants put of traditional pots without damaging them is such a hassle. Also frequently messy.
I'm not sure if any of these guys make transplant pots yet, but they really should!
Mine stay in plastic 2L pots from seed until they've sexed, often to a comical state like you've stated, then to there 10/15 gal final home.
Been using mostly the black felt grow pots along with some plastics since i started. Have always liked the felt ones, and they've lasted a long time for me.
Awesome of you doing this grow off to compare all this new tech in grow pots. Curious to see how they do compared to the old school ones, and each other.