I'm happy to be corrected, but at the moment I do not think it is possible to meet any of the following mapping requirements using either ArcMap or ArcPy:
1. Label measured grids using a format like 6828000mN where 68 is superscript, 28 is normal, 000m is superscript and N is normal
2. Label measured grids using a format that at least enables mN and mE to be included even if all the superscripting above cannot be supported
3. Label graticules using a Degrees, Minutes and Seconds (DMS) format where the minutes and seconds can be written as 00 rather than 0
Note that I have excluded Grid and Graticule layers from consideration here, because even if they can support these grid and graticule labelling scenarios they are not dynamic and I need the labelling above in a Maps On Demand (MOD) / Data Driven Pages (DDP) like application.