If you penetrate the EMAS, you'd get sharp deceleration, but the main problem would be that after 500 feet sunk in the EMAS, you's hit the "step up" to the actual runway surface, with still-significant speed. Could rip off the gear at that point.
There is no "ramp" or "step up" if you land short. It's the other way around -- EMAS actually sits "on top" of the paved surface. The "bottom" (base) of the EMAS is at the same elevation as the runway.
The issue if you land short is if the EMAS bed is too soft (think of landing into soft mud that's unable to withstand the aircraft's weight -- you can easily lose control). So EMAS including its base must be constructed to some minimum strength and density.
Since EMAS is actually "on top" of the runway surface, then there is in fact a ramp, but on far side. I.e., if you land
long, there is a gentle ramp
past the runway end that supports the plane
up onto the EMAS bed.