How can we improve WHMCS?

Services like ID Protection (also known as Contact Privacy) and managed DNS (or Premium DNS) are usually billed yearly by domain name registration service providers.

Did you know that as of now, with WHMCS, when an existing client orders a domain addon for an existing domain expiring in more then 1 year, he is only charged for 1 year. The remaining years are not billed (free) until renewal. In a scenario were the client just registered a domain name for 10 years decides, a few days later, to order ID Protection, he gets almost 9 years of free services. This is an important lost of incomes. There should be an option in WHMCS that allows for prorata billing at least rounded to remaining full years. For example, if a client with a domain name with a remaining period of 3 years and 2 months orders the ID Protection addon, he should be billed for at least 3 years. The setting should even allow the choice between "Round up" or "Round down". In the previous scenario, with the "Round up" option, the client would be billed 4 years of ID Protection. On top of loosing some incomes, some of us are even paying for these addons and loosing even more money.