I count my F1 containers as 1 batch each. But I have heard of people counting their F2's as batches, since from 1 container of F1 they could make 4 different F2 flavors, each their own "batch".

I count each F1 as a batch. I usually have 2-3 F1s going at the same time, I count each of them as a batch, so that's 2-3 batches at once.

I recently had to experiment with this because half of my F2's didn't fizz at all. I left them for like 2 days, opened them, and there was absolutely no pop, it was like I opened a bottle of water. I added some more sugar to them and left them for another 2 days, and 2 of them did get a lot of fizz, but the rest did not. I am not sure what I did wrong here, but I can say that it works, even though half of the ones I added sugar to didn't fizz, the other half did! So it does in fact work!

Also, at that point, I didn't care to measure how much extra sugar I put in, I just poured a little bit in each bottle.

I count my F1 containers as 1 batch each. But I have heard of people counting their F2's as batches, since from 1 container of F1 they could make 4 different F2 flavors, each their own "batch".

I recently had to experiment with this because half of my F2's didn't fizz at all. I left them for like 2 days, opened them, and there was absolutely no pop, it was like I opened a bottle of water. I added some more sugar to them and left them for another 2 days, and 2 of them did get a lot of fizz, but the rest did not. I am not sure what I did wrong here, but I can say that it works, even though half of the ones I added sugar to didn't fizz, the other half did! So it does in fact work!

Also, at that point, I didn't care to measure how much extra sugar I put in, I just poured a little bit in each bottle.

From my understanding and experience, yes. Even if you put it in the fridge but decide that you want it to ferment longer, you can. Just keep in mind that it will take it a bit to warm up to room temperature and to ferment to the point you want it to.