The only time the function is used is during a game list update. So firstly, ask yourself which is quicker: manually creating the dat and updating, or letting the FE do it for you. And secondly, ask yourself how often do you update your FE gamelist?
Speaking for myself, I let the FE take care of it. That, and I update my game list roughly once a year at best. There only seems to be 3D games being added to MAME recently which don't interest me in the slightest.