Weighing in on the girdle thing with my experience.
In 2003 I dynoed a megablock 4.15 stroke 4.50 bore 528 cube motor. Made 847 hp injected on methanol . I noticed cap walk on a crossbolted megablock, Max rpm was 7400. Bob weight 2432. I put a girdle on it. Didn't take away the cap walk issue. During this time we found a minor cracking the crank by #6.
I bought a rather expensive center weighted crank from Crower and took the girdle off. The C. W. Crank eliminated about 90 percent of the cap walk. I finally needed a little cleanup and align hone in 2019.
So IMHO the girdle basically can force a large portion of any movement into a vertical motion, which may help a little. BUT THERE IS NO TRIANGULATION to stop that vertical stress completely. So end result? IMHO they may be of some benefit, but not enough for a lot of stressfully builds.
Properly done, an add on girdle would be 3 inch or more tall, or thick, if that is how you would view it. That would require a rather short oil pan, like a dragster 10 qt . The big deal about it being so tall is it would now be so rigid it could transfer stress to the pan rails in all directions, not just lateral.