OK, so here's a few points I'd be grateful for some clarification on :-

The MkIII unit that I removed from my 2002 E53 was running V22 (3-1/63) when I replaced it with a Mk IV unit. My Mk IV is running V31.

The mention of "Navigation system operating software V32 is used on MK I, MK II, MK III navigation systems with split screen" is confusing me a little as I thought V22 was the final development for Mk III units.

I've never had any problems downloading/burning/installing the different mods, so is it worth temporarily refitting my Mk III unit just to do the mod?

I am aware that I'll have to burn 2 different versions of V32 to use in my Mk III (CD) and Mk IV (DVD) units if I proceed.

Secondly, having modded the pointer icon and splash screen on my Mk IV, will I have to repeat this exercise before I burn V32? or will it remember those changes from V31?