My opinion? It's easiest to just cut and paste what I posted in another thread within the last hour - but the summary is if he lasts til the 3rd round, at that point I think the potential upside would counterbalance the risks and red flags.
I might have agreed a week or 2 ago but now I'm adamantly against it. Gase requires a complicated playbook and Jackson's 13 Wonderlic Score does not exactly build confidence. Relatedly, it's been reported on ESPN and NFL Network that he was the least impressive of the bunch diagramming white board plays.
Now above and beyond that, someone here posted the relative velocity of the QB class's respective throws and at 49, Jackson's was the discernible lowest, so there's that too. Florio today was reporting that one team that wants to interact with him placed 7 unanswered calls to him. Relatedly, his decision to use his mother as an agent speaks poorly for his judgment; a good agent could and would have anticipated that he needed prepping for the Wonderlic, could have neutralized a lot of the resulting negative news and certainly would have not let any interested team's calls go unanswered.
Way too many red flags for me so no thank you. Now if he fell to the 3rd round, which of course he won't, then I can see where the relative gains could justify the risks.