Oh, but Sami kept insisting he had "changed", which of course he had not, just kept it hidden from her. In Jack's case, he beat himself up for 3 years, so it was a long, long redemption for him, Jennifer had a long, hard time, but did a good job.
I just cannot see Stefan being redeemed. I agree, he is "just there", very little dialogue all this while. But his hangup over Abby, his realization he could have her, as long as she was Gabby, his failure to let anyone know she was ill, get her help, and even after being throttled as he was, being found in "afterglow" with another man's wife, he does not want Abigail getting help, he wants Gabby out and with him.
Even in the hospital bed, he is just "there".
And while I have not seen any indication of Stefan leaving the canvas, cannot recall seeing behind the scene pics either. But then, that has been true since he arrived in Salem. Makes me wonder if the actor is not all that happy with his character, his story, etc.