I haven't watched him game in and game out. But looking at the highlights, he doesn't seem slow out there. He'll be like his brother, who is 6'4" and 238 lbs and is mobile.
I don't expect Florian to be that heavy. But I think he'll be fine being over 200 lbs. I don't think it will affect his mobility that much. I think he'll just fill out into his man body.
Of course, having guys that size is a bonus because big boy hockey in the playoffs needs big boys.
I don't know why, but I picture Xhekaj at 6'4" and eventually over 200 lbs on a line with Luke Tuch, who is listed at 6'2" and 215 lbs. Just two big bodies on the bottom-6 causing headaches and havoc on the forecheck. And we'll see how they do as pros, but at their respective levels, they've shown some offense.