toyzilla,
in the mid 1970's, Allis Chalmers & Yale both developed somewhat of similar system for Ford Motor Co - it was called and inch lb over load device. Basically, this device measured the deflect of an extension of one of the tilt cylinder pins. The devise would prevent the operator from lifting a load above the rated capacity, prevent a rated capacity load from being tilted forward. It was fitted to both electric & ICE forklifts. It had issues but did what it was supposed to. But the biggest issue was the UAW drivers that didn't like it - hard to fix that. Fully realize that
The biggest issue any manufactuer faces when one makes a safety related systems standardd and then later tries to remove it for cost considerations - like to be competitive in a satur- lawyers have fun with those situations - like trying to remain cost competitive in a saturated & in my opionion stagnate growth market like fork lifts that has an abundance of competitors & more coming into it..
So it is simple, they don't elect to do it.
Also part of the SAS system is the fork leveling system - seems that feature is commonly available thru Cascade - no Toyota patented or proprietary feature there - what happened???