If he is our 3rd big he will almost always be playing with either Gobert or Favors, so you can sorta hide his defensive deficiency a wee bit. He does have the length anyway so I don't think he is actually all that bad. Offensively he would complement those 2 really well with his ability to shoot, to drive & dish, etc.
I know many here would prefer Tomic and we can use our pick on another player but I think 3pt shooting nowadays is quite important for a 4 guy off the bench that Kaminsky would be perfect in that role. I can't tell you how many times I wish Booker can has an open 3pt shot that he just doesn't have the range of confident to take. Swap him with Kaminsky and let's make music.