Loci honey,
I did a little checking into Tapper and his great 40 time but the hamstring issue that prevented him to run the cone and shuttle.
Other may laugh at this but I realized that in my short search, I found many examples that do not run the shuttle and cone due to hamstring 'injury'.
First, there is Myles Garrett who ran a 4.64 40 but no cone and shuttle (no explanation why)
Another player of note is Michael Bennett - 274lb
He ran a 4.86 40 in his pro day but also had a hamstring issue that prevented him from running the cone and the shuttle in both the combine and the pro day.
Perhaps their agents are the ones who remind players that are more straight ahead speed guys that the hamstring are injured so they should not cause further injury by running the cone and shuttle. Guess the 40 is ok because it puts less stress on their hamstrings.
May be Seattle discovered the wide-9 overcomes limited agility?
So they have been able to get these players with speed to play well for their system?
Though Casius Marsh, a 250lb DE did have a decent 7.09 cone though with a 1.66 sec 10 yard split (Tapper is 1.59 sec, Bennett is 1.62-1.78 sec).