One of the reasons I think Logan Wilson was ready to make a deal, is he had only made 4.9 million in his 4 years in the NFL (3 after taxes). So while he was "wealthy" by normal people standards, not by NFL ones. So when he had the chance to lock in a 36 million $ extension with a 10 million dollar signing bonus (6 after taxes), he immediately in one morning doubled the entire amount he had made in the NFL.
As for Tee, he will have made 8.7 million total by the end of this year in his career, (5 after taxes) ... But if he signs an extension right now, he could get a signing bonus of at least 20 million lets say (12 after taxes). So, like Logan, he could double his NFL earnings with one stroke of the pen as well, and get himself security from injury. If he doesn't sign all the playing risk is borne by him, which is why it would be irrational to do it. Even practicing he could suffer a season-ending injury. So I am not sure why his agent would have him doing anything until the new deal is done.