The biggest issue with accelerometers in a non-pinball cabinet application is the placement of the sensor and construction of the cabinet. Pinball machines are a long box, held up by 4 fairly thin legs. By their nature, they wiggle a bit, and aren't too difficult to shove around. Standard arcade cabinets (even bartops) are usually designed to be pretty sturdy in the directions where pinball nudging forces are likely to be applied. In a bartop, I'm not sure you would want to be sliding the unit around while playing either.
If nudging is a big part of how you play, the ultimate solution is to de-couple the panel from the cabinet and build some self-centering "slop" into the coupling of the control panel section to the cabinet, and build whatever nudging sensor solution you desire into that more easily movable section.