It's been a long way, and a lot of that time has been spent barking up the wrong tree, but the E-Commerce 4 QuickPay module is getting somewhere.
As eC4 doesn't (yet) quite grasp the concept of 'authorized but not captured', ec_quickpay have to modify the workflow somewhat. Being eC4, the problem is not customizing it, the challenge is to figure out the best way to do it. Should it modify the existing workflow rules from ec_store, or should it disable them and create it's own? The latter is probably the most robust solution.
Hopefully I'll get the last things sorted and cleaned up soon, so I can get a beta release out the door.