I came across an interesting thread from Kurt Miller over on the brainenos.com forum. Mr Miller is well educated on the Benelli platflorm especially in 3gun modifications. He has come to the conclusion that the poa/poi variances with some Benelli's are due to a misalign magazine tube. Pretty much the gun is going to shoot in the direction the tube is pointing due to the slightly loose fit of the barrel into the receiver. He has developed a jig to eliminate this misalignment and I think some of the top 3 gun gunsmiths now have them. The catch, the jig may only work for the M2 12 ga. So, if you have one of those with that issue your in luck. I don't know if the jig would work with any other Benelli model as I've never contacted anyone about it. The thread I read from Mr. Miller was from 2013 so its possible things may have advanced. I may check into it further. Thought some here may find this beneficial.
I have spoken with Benny Hill of Triangle Shooting Sports and Taran Tactical regarding the jig. Unfortunately, it is only designed for the M2 12 and has not been modified to accommodate the SBE's or the M2 20 ga.
Benny and Taran still use barrel bending methods to reconcile poa/poi issues on the m2 20's.
Thanks for the updated info.