Matt,
I think this is a good approach. You've got a plan and are doing things incrementally. Superman wheel rollout are tough. The first time I did them I eked out eight reps by force of will and was extremely sore for weeks afterward. Needless to say I haven't had any desire to do them since.
Better to plan and do things like you are doing. BYW, many very fit individuals who have come by John's office could not even do one repetition of the Wheel Rollout. On the converse, this was a favorite exercise of the late Ronald Reagan, who liked to show off to his cabinet and advisors what he could do with them.
Greg