Byram is actually a reasonable player to make a bet on assuming he remains healthy and most importantly steers clear of his concussion problems. He has potential, and he was a dependable player on a stacked Dcore during the Av's cup run. That said, his play hasn't improved from last season and his underlying analytics aren't great. Combined with his concussion risk, that's a lot to bet on to overcome.
Colton + Byram for Mitts would be worth thinking about, but I think both of those players are unlikely to grow into a position where they could be impact players similar to that of the level of Mittelstadt, who is one of the Sabres' few consistent/good forwards. I think you only consider doing that trade if you think Cozens AND Thompson can return to form as legitimate #1 and #2 centers, but considering their regression this season, it's murky waters right now.