Not sure if any jacket BCs are adjustable like that. I only have back inflates at home. I've got a Zeagle Stiletto, Laser, and Zena at home. The Stiletto and Laser both have cummerbunds that do have some adjustability besides the velcro and clip adjustments. Each side of the cummerbund has two mounting positions. So, if necessary could be moved to accommodate smaller or larger individuals. The cummerbund sides are secured by a couple book screws and are mounted in grommeted holes. There are 4 per side, IIRC.
So, I'd recommend heading to a dive shop and taking a look at how the cummerbund is attached. I'm not sure if any of the jacket style have that level of adjustment.