I think you're right in this case. I haven't looked at the problem in about 10-15 years (before Stripe had recurring). I remember there being a ton of end cases

I think you're right in this case. I haven't looked at the problem in about 10-15 years (before Stripe had recurring). I remember there being a ton of end cases I had to deal with. We ended up going with Recurly due to it.