Seal Subscriptions App

First of all I will of course give full 5 star for that app - it works just as intended for me while other deposit/subscription app simply don't, it's quite customizable and easy to use. It's fully integrated with credit card and PayPal payments, which is fantastic. I really enjoy using it.

I would rate, however, even 6 stars if it would be possible, if this app would cover all major use-cases of preorder functions and payment in installments (which I use it for):
1. Don't create a new order on a subsequent purchase (because in the installment scenario it's just a payment for original order, not a new purchase) or let me replace ALL products automaticall in the product automations instead of each by hand
2. If the app is removed from a specific product, the widget still remains on the product page - super weird. For example, I don't allow partial payments for goods that has been released. Customers can still do that because the widget does not go away.
3. It would be nice if I could add a surcharge for subscriptions, because I'm interested if customers pay me full price when preordering instead of paying in installments, so I want make installments more expensive. Or, the opposite - make a discount on the full payment.