Once at the MDA if not visual, fly level to the MAPT then if not visual the MAP ALT is set
I'm curious as to why you would then fly level to the MAPT if you're already flying a constant descent? If you're at the MDA where the approach plate says you should be, then anything past that is simply going to create an unstabilised approach when you have to 'dive' to get back on profile.
morno