How can we improve WHMCS?

Currently the only way to set up a direct debit is to pay for an invoice. I'd like to see a management feature similar to what exists for credit cards where mandates can be set up in advance. This will be useful for existing clients who want to create a mandate for future payments without having to wait for a new invoice to be generated first. It would also give them the ability to easily cancel the mandate from there as well.