Hi and thank you for your input.
There are no Stripe API limitations for this (at least none that I know). The reason why this wasn’t implemented is the idea to keep Stripe API requests at lowest level possible. However, I can see this can be implemented via webhooks. It would require one additional API request per each installment payment, but since it’s gonna be made asynchronously (without slowing down or affecting customer’s experience), I think this could be done.
Will research this and get back to you.