I can see how it can be a big deal with ABS functions... but with airbag depolyment?

Airbag deployment is the end result of tripping triggers that are placed in strategic locations within the vehicle. These triggers are usually some kind of magnetic switches where the circuit is completed if the force of impact is great enough to "flip" the switch. In most systems the airbag would only deploy if more than one switch has been triggered due to impact.

At 2.2% difference I don't see how the effects on the ABS system would matter much. If you are triggering the ABS left and right then you're breaking way too late and way too hard... and if your airbags have deployed, you've got other things to worry about besides that 2.2% difference.

What this all boils down to is that when you make alterations, you have to expect that your vehicle has been alterred in more ways than one... and you have to adjust your driving accordingly. As long as you are subject to the laws of gravity and physics, no amount of mods will make a 4k lb VX with high center of mass handle like a Porsche 911.