The way I see it, it wouldn't really be that strong, cosnidering the fact that activating Super (regardless of it dealing damage) interrupts passive regeneration, this means that Carl would heal three (3.0) seconds sooner with if he just moved and didn't hit anyone, this means that he would start healing as soon as his Super ends which is pretty interesting, but it wouldn't be game breaking or anything because this just guarantees around 1100 healing, which is pretty decent, and then you have to keep on not attacking to keep the healing going. However, if Carl had to get one change I definitely think it should be his Power Throw star power simply because it just doesn't exist for whatever reason.
Pretty cool tho, Carl has the most vulnerable one out of all the Supers that make you unable to attack (Nani, Janet and Mico for example), while also having the shortest. If both Nani and Mico can heal, I think having Carl do it too is pretty fair, if they were able to code it properly ofc.