You should have some target budget you are willing to reach (you mentioned restocking). If you are running a budget of 10 per day and your target is 100, scaling by 10-20 percent every week is a waste of time. If that’s the case (10 – 100), test something like 10 to 20, 20 to 40, 40 to 75, and 75 to 100.

Somewhere in between you will probably see roas decrease. That’s where you will want to optimize the campaign: create more ads, create a better audience, remove placements that are suboptimal.

As to duplicating campaigns – that’s an unnecessary mess.

Good luck!