Looks like the extra length is mostly aft of the rear cargo mount, which should help opening the rear latch on the Pelicans/Hardigs, and better still, eliminate the urge to ease the box forward which hampers turning radius.
Brilliant, brave, and commendable to re-tool and innovate. You can NEVER address every idea or request, but that mod by itself kills many, many birds with the same stone, and probably expands potential BEYOND what many requests had petitioned for or imagined.
Less pondering. Simply march ahead, to the ends of this majestic planet.