I'm a mechanical designer, not an engineer. From that perspective, here's a "seat-of-the-pants" answer:
I bet that the Rhino system would lessen the force and stress placed upon the top-break latch.
The difference wouldn't be much, but there'd be a difference.
It's a matter, I think, of angular momentum. If the recoil force were higher up, it would get a "running start" due to normal tolerance-looseness. Lower down, the force would have less starting room.
What do you think, Dan?
Jean and I will be away visiting our brand-new, second granddaughter from June 29th through July 7th.
Our daughter, the girl who swore that she would absolutely never reproduce, has delivered!
Not only that, but the baby, little Moya, actually is quite pretty!
We're very happy about the whole thing.
Please keep everyone polite and factual for me.
See you again on the 7th.
I'm not DAN, but the Rhino system would lessen recoil stress by minimizing the upward "whip" by virtue of placing the opposing forces more directly in line. The barrel whip of a revolver in recoil is caused by the rearward force of the fired round (directly rearward) being opposed by the resistance of the hand at the grip being much lower.
Remember the old Russian "Hacksaw Pistol" of a few years back? Recoil was the same, but muzzle flip was lessened.
Yeah, OK, but that "upward whip" of which you wrote would serve to help hold the break-action closed, not to open it.
Nevertheless, the major force involved is the rearward shove from the being-expended cartridge, in Newtonian reaction to the forward-moving bullet.
That tends to violently separate the break-action, and to rip it open. This is why the top-strap is in tension, all of it focussed upon the hole into which the upward projection of the frame fits.
I'm about to get in way over myhead here regarding the "upward whip", but here is my experience:
I had a customized Colt Single Action Army .357 Magnum that had had a Smith & Wesson rear sight installed in the top-strap. I was firing some heavy .357 Magnum loads and noticed my groups were climbing out of the black at twenty five yards. I was puzzled by this as to why they should stray. Then, after reloading for another string, the hammer was nearly impossible to cock. I examined my gun and noticed the rear of the cylinder binding against the top strap, and further, the barrel angled down noticably.
After I cleared my gun and left the range, I went to my gunsmith and we analyzed the problem. The inertia of the barrel makes it tend to stay on line with the target as the gun recoils. The top strap, weakened by the milling, stretched under the recoil forces. The standing breech still maintained its correct angle to the lower part of the frame, only the top strap and forward section of the frame "gave."
I thought I had reduced my Colt to a parts gun, but my gunsmith was able to re-align the frame, and I no longer shoot heavy handloads in this Colt.
That is why I assumed the top strap is in tension from "barrel pull" rather than back thrust from the case head.
All of the foregoing is only my surmise, not any educated engineer's calculations.
Sure would like some more authoritative input than I am capable of.
P.S. Congratulations on that second grand daughter, and hope you have a very pleasant visit!