I think you have to get a resolution on whether he's in line to be suspended or not for the DV conduct and obviously do some due diligence on his character (the whole situation was pretty ugly). That impacts what kind of deal you can offer, whether it be a one-year prove it deal or a longer term deal (would have to be structured to walk away if more trouble ensues).
From a pure football perspective, he would be a great addition as another edge rusher, which I think is a huge need.
I'll trust PC & JS on whether they pursue or not. Given the DV thing, this also has to include Allen in the decision making process as there will be criticism of any team that signs him.