I would concerned with skill caps, also. Like changing Deep Threat WR with 98 speed and 5 caps but no Take Off ability unlocked yet. You are saying you can change him to "HB - Receiving Back", then back to "WR - Deep Threat" in the same offseason week and now he has the gold Take Off ability for free.
But does he now have 9 caps because it re-rolled his skill caps?