I like Semi but I'm not sure I hold him in such high regard as some others on here. He's made a couple of decent breaks and scored a good try from a pick and go through the middle of the ruck, but otherwise I'm not sure I've seen him do anything particularly amazing. I accept that he's not been given that much of a chance, but based on what I've seen I'd have Evans, Lawday, Chisholm, Robshaw and Dombrandt in the team before him, and Clifford when fit too.
He clearly offers something completely different from all those guys - the Fijian 7s style of play, incredibly offloads, rangy running, attack from anywhere, possibility he'l make something happen from nothing. Unfortunately, in 15s, the backrow players have to do the basics first and foremost, with the flashy stuff as an added bonus. Maybe Gustard prefers the names mentioned above on that basis.
I am happy to see him on the teamsheet, but not necessarily unhappy when he misses out and while it would be great to keep him, I think it's one area where we would not miss him hugely