We have some process issues with our store, just throwing it out here to see if anybody has a bright idea.
We have a product that is under development but we want people to reserve the product so we know roughly how much we need to create. Currently what we have is a payment method called "Reservation". This payment method allows you to create the order without paying. Problem we have is that sometimes people choose Reservation for other products and we need to cancel them etc.
I tried a payment method restriction module but that doesn't work in our show due to our payment provider module. And we always have the problem "What if they put a normal product in the cart and a reservation product"
So that's why I added this subject, When product X only allow that product in the cart and show specific payment method