Well, in my mind it was pretty simple - it just transforms all the geometry (once) from the current (chosen) plane (CPlane) to world. Finito. There is no constant transformation, the geometry gets moved exactly once. I imagine on a big/complex file this might actually take some time and the user will have to wait. The only difference between this and doing it with RemapCPlane is that it acts on all the hidden/locked objects, not just the ones the user has selected as in that or ExportWithOrigin.
For me, the complexity involves figuring out how to deal with all the non-geometry issues I mentioned above - named views and CPlanes, layouts, etc.