Isn't there KAM profile, which is KAT profile but all one row? These are well-liked profiles, Jamster, so you could try that.
MT3 is not a modified SA. It was designed from scratch to work with modern MX keyboards using modern angles.
Unlike SA, which probably was designed for keyboards prior to the Model M, which had different angles and sculpts from modern keyboards, MT3 is aligned correctly with the MX stem. It is a deep-dished spherical profile. I don't remember if it has sharp edges, but the spherical dishes on the keycap surfaces are very comfortable and deep. They are intended to evoke the old beamspring keycaps, but at the correct angle.
I've used SA and typed on MT3, and MT3 is a million times more comfortable. It takes some getting used to, but it's more like OEM on your fingers than SA. SA profile is going to decline in popularity as KAT and MT3 are modern designs that are much more comfortable for most people. MT3 is the only spherical that I enjoy typing on.