Hello,
As Nicolas wrote:
that means that you'll have the points payment method in the list of the payment methods, and when you finish the order, a coupon will be added to the order and you'll get back to the checkout
I don't see this as user friendly
The "user points" payment plugin was just a payment plugin and it has evolve with time.
Because it's still a payment plugin, it need to still have the previous features and it cannot move forward.
My opinion is that it should become a classical HikaShop plugin and not a payment one ; so it can have restrictions which won't be handle by the payment system but by the plugin itself.
It requires some development but, I think, that's the best way to improve it by removing his "payment method" feature.
Regards,