Good article on the impact of Comp Picks on free agency, and how the next wave of FA may not be until after May 7...
https://deadspin.com/how-the-rise-of-comp-picks-is-chilling-nfl-free-agency-1833782354
Compensatory picks have been a low-key feature of the NFL draft since 1994, the year after free agency finally became a thing. But this offseason, more and more teams appear to be finessing the free agency system in an attempt to to stockpile comp picks. And it’s created something of a freeze on the free agent market.
...Timing is important because any free agents signed after May 7—the second Tuesday after the draft—won’t count against a team’s comp pick formula. As a result, teams would prefer to wait things out, and so veteran free agents run the risk of losing a potential roster spot to a much cheaper draft pick.