The difference is that 1) SBS isn't nearly as popular ("common use" thing) as SBR and suppressors and 2) we cannot demonstrate or argue that there's really no practical difference the way we can when considering a pistol with a wrist brace vs. a short rifle, because other than muzzle loading, antique or C&R guns, there is no lawful way to own a smoothbore weapon under 26" OAL or a stocked smoothbore with <18" of barrel. Let's be honest; how many of us, especially those under 40, have drafted wills, appointed executors, and filed with probate court? Because there's no guaranteed amnesty even for legally appointed executors (just ATF policy, which can change at the drop of a hat), and not even implied amnesty for acting executors/administrators in the event that one is not legally appointed. Again, the advantages are that any trustee can legally (by statute, not currently permissive agency policy) take possession of the weapon in the event that another trustee passes, and that any trustee may legally lend or transfer any NFA weapon owned by the trust to another trustee with no requirement for supervision. That has implications beyond simply borrowing, including that a trustee has to move somewhere that disallows NFA or has an AWB. It also deals with a situation where a trustee gets themselves in trouble and can no longer possess firearms; if an individual form 1 or 4, those items must be surrendered. But with a trust, the offending trustee is removed from the trust, and the remaining trustees may keep or dispose of the expelled trustee's weapons. Out here, the CLEO sign off "side step" means nothing more than saving a 22 mile round trip; our sheriff is happy to sign, as is the sheriff in my sister's county. That is not the reason we chose a trust.