I now have a few of the one piece tubes.
The tube pictured above takes the 22" VM tactical from 8+1+1 to 9+1+1.
I've been testing a few shotguns with heavy buckshot and slugs using a factory tube and the one piece tube. The results have been favorable. This simplification is probably not "necessary" but it keeps POI from shifting if the shotgun is disassembled and makes the tube less prone to failure and flex at the hinge points. The other methodology involves a lot of work and epoxy and precision. I am not sure if Remington will see the need for this on the R12, however, a one piece tube, if done for both the benefit and cost savings could reduce assembly and manufacturing costs slightly.