It's lazy to assume that because a 17 year, 5 month old guy scored a 27 inch vertical, that he probably would score the same again as an 18 year old, or a 19 year old.
Most bigs don't even do the vertical jump because people overanalyze it, or if they do, they fudge the standing reach so the vertical looks bigger.
Larry Sanders and John Henson are just two examples of guys who had an enormous reach and good athleticism, but only scored about around 28'' to 30'' max vertical, both as 22 year olds.
We wouldn't even be having this conversation if Bender declined to do that portion of the testing and only did measurements.
I'm reminded of that scene in Interstellar when Matt Mcconnaughey asks the teacher what his pant size is and then says, "You mean to tell me that it takes two numbers to measure your own (butt) but only one to measure my son's future?"