The R.O. comes with a fairly pronounced bump already, I doubt you'll find a replacement much different. The Wilson in the picture above looks super pronounced because the area above it is cut in deeper. It wouldn't fit on your gun anyways.
Try sliding your hand around to the back of the grip a bit more, that should make it easier to get your thumb on top of the safety (you only need to ride it to keep from bumping it back on, no need to put a lot of pressure on it) and de-activate the grip safety. If that causes trigger reach issues, I'd look at the grips or maybe a shorter trigger (the stock R.O. is a long trigger) option.