2 seedlings, one cup.

You can look in my diarie there i have one auto in a pot with a photo the auto is realy small but it lifes

ive played around with this previously and currently got some bush seeds i tried it with just some baggies, and ive only got 1 left now out of 2 in every cup 3 cups... imo they seem to tangle and 1 starts to die off fairly quickly as they strangle each others roots mate. id advise keep them seperate for the strongest growth, although if the space is an ssue may the best seed out of it win!! note: if you manage to get to a transplant stage which if youre going to do this id do it rather early on and be very fragile with some phd or ro water in a bucket and soak the roots softly and seperate the dirt from roots and very cautiously you can save the 2 and then transplant into the seperate forever home, but to harvesta 5 gal pot, even 7 upto 10 i say would be too small for 2 autos in same pot mate, like you said feeding, sorry for ramble on but hope you get my opinion :)

At this stage you can try to separate them an transplant or see which one is stronger of the two an pick one an cut the other.