I’ve seen the screenshots of Luke’s appearance in TBoBF, and one thing that bothers me is that they made him look younger than in RotJ, even though it takes place a few years after the Battle of Endor.
They didn’t. Take a look at the movies he was in around 1994. I googled that the other day and found it a surprisingly exact match to how he looked then.
And Mark is a voice actor. A very good one. I believe the voice is his, but they have adjusted it to sound younger. I found his appearance in the episode to be very well done.