There's also a non-zero chance he becomes Kevin Obanor or Tanner Groves. Maybe more realistically he becomes Iowa States' Aljaz Kunc or Tre King. I'd prefer that over an unskilled big like Robert Jones.Mast is a stretch 4 who will probably have to play as an undersized 5 on defense to avoid getting exposed. It looks like he has about as much athleticism as you'd expect from a 6'9", 240lb white guy. He will be a guy who you have to hide on defense when he's on the court.
The Kalu comparison isn't exact, but there's a non-zero chance that Mast goes the Kalu route if he comes here - unable to get on the floor because he lack the athleticism to defend or rebound at a high enough level.
It's funny to talk about athleticism and defense like this when we play DDJ 30 minutes even when he's overmatched by bigger guards, or Nolley 30 minutes when he's completely disinterested, or Davenport 20 minutes against anyone. Clearly Wes will accept poor defense if it can be made up on offense. Looking at advanced stats if you prefer those, Mast has a 1.4 DBPM and 0.5 DBPR, both better than Ody.
I really don't know what you're looking for in the portal. If guys can't rebound at a lower level, how are they suddenly going to rebound at a higher level? We can talk about intangibles all we want, but at a minimum any big we bring in has to have put up good rebounding stats IMO. They don't grow on trees. Rienk Mast did put up worse numbers against top 100 competition, but he was the best player on a top 90 Kenpom team with a defense ranked #62. I think it would be insane to turn that down. How many guys better than him are out there? EvanMiya ranks Mast as the 7th best transfer overall and 3rd best big man.
One aspect of his game that is appealing to me is he hits over 50% from midrange. Our offense is way too midrange heavy, so might as well bring in guys who can make them.