The more I think about it, the more I really wish they'd used Ted's talent for what it's worth. It was nice to see him for a second, if only as a delusion.
And I have a feeling he'll be showing up down the line - not cutlining because this isn't concrete!
I agree, Ted is definitely underrated, and even though its probably not the most demanding role for him to play Chet, there's a few spots where his acting talent really stands out, first scene to come to mind is the bar where he talks about his stories from Desert Storm. It seemed to me like it was meant to be just a dark joke, but there was something very touching in the way he played it, you could see the pain that Chet is dealing with (or rather not dealing with) and it truly humanized the character more than just being Ash's fucked up, party animal friend from high school. Hopefully, if he doesn't show up again this season there will be another role for him in season 3!