That $20M/yr sounds like uncle Keyshawn whispering in his ear. He's good but he exploits smaller CBs. He's fast for a man his size but not in terms of pure speed. If he was 5'11" running 4.57 he would considered average in terms of long speed. Vincent Jackson was 6'5", with better verticle tests, similar agility, 241 lbs and ran a 4.6 to put things into perspective. With 3 years experience and wants to be the highest paid WR? He's no Antonio Brown....far from it. Considering how he could just as easily flame out after a year or so of getting the contract, Loomis would be foolish.
Give him a reasonable base with $20M type incentives. If he plays up to that level he gets paid, if not he doesn't. I think all contract should be that way, i.e. put your performance where your mouth is. If he wants to be the highest paid then he should play like he's the best WR in the NFL. Attitudes like this so early in his career is a huge red flag.