Are you sure about that? On Form 2210 I don't see anything indicating you need a waiver just to use the annual income installment method on Schedule AI. It does mention waivers for underpayment due to certain hardships, but that's a different matter. I haven't actually done this myself in the past, but was expecting to for 2019.
You're right, you can use schedule AI rather than a waiver. That doesn't really change the point, but I was incorrect, thanks for pointing that out.