I want to make sure that if I purchase the Standard license today, if in the future, I need any features only supported on professional/premium, I am able to do that by paying the difference?
There isn't an automatic upgrade procedure on our e-commerce yet but it's planned.
If you or other customer, would need such an upgrade before we improve our ecommerce, they should put a direct support email: we will produce a discount coupon to enable it manually.