That's where Lamar not having an agent is going to make trading him more difficult on the Ravens as well.
If they were going to tag and trade, the agent could be communicating with teams to guage if they could get a deal done to even make the trade feasible.
I'm sure the Ravens are factoring that into their decision.
Lamar and/or his agent if he had one would need the Ravens permission to negotiate with any other teams (assuming he's hit with the exclusive tag). Maybe he's allowed to negotiate after the Ravens apply the tag but before he signs the sheet, but I am not sure about that.
If they're gonna look to trade him, they'll probably grant that permission, but not definitely. Watson's trade appeared to be contingent on a deal, but WIlson's wasn't, for example. Ravens could allow Lamar to seek out his own deal with one of the teams that are interested or they could tell those teams they need to trade for him without knowing. Plusses and minuses to each approach, in terms of leverage for getting the best trade return.