Some CCC's report how much you pay each month. Under manual review, they can see you are using your credit cards, so no worries.
Others do not currently report your payments to the CRA's. It is unlikely to effect your ability to get a loan (auto, mortgage, etc). However, I would be a little concerned about a CCC not wanting to extend credit to someone who doesn't use the credit cards they have.
My personal philosophy is to let the statements post with whatever I charge in a month. Then pay if full before the due date. With multiple cards reporting, my score is not maxed out most months. But I can quickly max out the score by prepaying for a month. For me it is mostly about convenience.
If I was worried about my credit score dropping enough to trigger AA, I would probably limit the number of cards that report a balance. But one card reporting $1 and another card reporting a small balance is very unlikely to trigger any kind of AA. Having two cards report a balance will not optimize your score for that month, but it is easy enough to maximize if needed. So I think it is fine to let two cards report a balance if you don't mind the micromanagement. Or letting only one card report $1 would also be fine. Or you can be like me and let most of your cards report a balance and pretty up your CR's as needed.
