Two would probably cause problems. You'd be looking at your highest probability of aborting fry there as the space is small to begin with and fish that birth want more space before birthing.
ok cool,
good luck with the babys,
ive just got loads of baby swordtails from 3 of my females so theres alot,
had one in divided breeding tanks and one had them in the tank so didnt get them all
WHat someone mentioned awhile ago was getting 3 or 4 and kinda cutting off one part of each one and sewing them all together so it was a REALLY big net breeder.
Coconut shavings will eventually decay, but it's probably not going to happen in the time you're using it to hold your nets together. As long as you aren't using them for an extended period of time. I'd replace them regularly.