Hey man, stopping in again to check things out. Glad to see ya got some healthy babies popping up!
Once there is roots shooting out of the peat pellet, plant into the 5 gallon containers, completely skip the solo cups because an autoflower only has such a long veg time (2-4 weeks most times).. If you have to do a transplant in between you risk stressing the plant and it may not grow for a couple days. Since you started in peat pellets this is the simplest method, just don't overdo it with the water and spread it around the outside edges, not directly at the peat pellet, this will help get the roots growing and searching for their water.
That's what I would do anyways, not saying you have to ^^^ I go from solo cup to final container but only because I start everything in a solo cup or a bit bigger container and transplant at 2 weeks generally.
As for nutes I would wait until they have established the first 2 nodes some, closer to 2 weeks old. The cotyledon leaves store enough energy to keep a plant going a couple of weeks without added nutes. Again, that is my preference. 1/4 strength shouldn't hurt them but ya don't want to overdo it either
Looking great otherwise and like I said, once you see roots coming out of them peat pellets get em planted. That way you don't risk the roots getting to much light or getting rotted.