Yes, you can edit the results of VRIK if you need some different behaviour for the arms or whatever. Final IK components work pretty much like layers of animation that can be additively stack on top of each other together with some custom code if necessary.
Here's a video of a mocap-like solution that uses elbow trackers. It uses a little additional script that runs after VRIK to rotate the upper arm towards the elbow target and forearm back towards the hand target. You can get that script and the demo from here.
Note that since the arm only has 3-4 bones, you can choose between elbow accuracy and hand position accuracy. With the elbow tracked solution, you'll loose some hand position accuracy just like you do when you retarget Humanoid animation from one character to another in Unity. It happens beacause the bone length proportions are different.