As a skydiver, I used a device called an AAD (Automatic Activation Device) that would detect ground level, detect an airplane ride up, detect freefall, and monitor altitude on the way down. The idea was that if the AAD's on board computer detected that I was still in freefall at 1000 feet, it would activate a pyro-based cable cutter that would deploy my reserve so that I did not freefall into the ground.
Pretty much every dropzone has signs everywhere reminding people NOT to turn on their AAD and let it calibrate anywhere except the landing area, because if the device were calibrated elsewhere, it might either a. deploy a reserve canopy in the trunk of a car, b. fail to fire when its owner lost altitude awareness in freefall, allowing its owner to crash into the planet at triple digit speeds, or c. deploy a reserve parachute that would entangle with the main parachute, resulting in its owner crashing into the planet at triple digit speeds.
I say all this only to point out that barometric devices can be tricked, and I applaud the INTENT of the rule. I am not sufficiently familiar with HPR procedures and equipment to know whether the rule has unintended consequences, so I have no opinion on whether it is a good rule.