I work in a multi crew aircraft, which can climb like a "rocket ship". We use the continuous decent method whereby decent maybe delayed to facilitate a constant rate to the MDA from the IAP/hold. Once at the MDA if not visual, fly level to the MAPT then if not visual the MAP ALT is set, if visual, circling ALT is set. In the case of a precision approach, the DA is set on the ALTSEL and the DH set on the RADALT. At the DH/DA the MAP is initiated and the non flying pilot sets the MAP ALT on the ALTSEL.
My reason for asking is simply for curiosity. A discussion based on pros and cons of our method versus others of setting the MAP ALT from the commencement of the approach as a couple others have already stated.
Hope this answers your query.