Redskins free agent signings 2018

[metalskins]

So, I'm going to be the resident conspiracy theorist for a second. If these free agents, of whom the 'skins drafted and developed, sign with other teams, I know the 'skins get compensatory picks. However, is there a certain amount of time in which that goes away? For instance, say Breeland or Grant don't get picked up until the middle of the season, what does that do for the 'skins getting a compensatory pick for these guys? I'm asking because I wanting to learn how this works. Do they need to get picked up prior to the season?