I read through it and didn't see anything too terribly related upon my glancing. Personally, I can't see how there would be any more operating stress with a CO2 mag that is regulated. If it's regulated, the mag should be exerting the same amount of pressure on the slide as propane would.
The blow back feels the same with the propane mag and the CO2 mag. There is no noticeable difference in the forces exerted between the two. If there isn't enough of a noticeable force in the blowback, then I would have to say that using propane would wear down the gun just as fast. That's just my thoughts though. If anyone has any actual hard technical evidence about CO2 being bad for the gun, I would really like to see it.