The ability to limit of select the duration of a subscription in addition to the increment for all products.

Eg. You have a course that sells for $500 and offer a monthly installment plan of $100 each month. It will be great to be able to set a number of installments to 5 so you don't bill client beyond the 5th payment without having to manually terminate the subscription plan.

Also, the ability to specify the expiry date of sale pricing.

Eg. You are offering an early bird sale that ends October 30th and set your original/strikethrough price at $500 and the early bird/sale price at $425. It will be helpful and efficient to have the price automatically revert to the original/strikethrough price on November 1st.