notice where the problem is. it’s around the pinions for the hands. also moisture should not affect enamel like this. for a $250,000 watch should not occur.
I find the MR is in general more interesting because of the engineering involved. However, from a practical standpoint, the ST is better and more useful IMO (and yours it seems)...
But the engineering that goes into making this chime each quarter hour is quite amazing to consider. Looking at Nicolas’ question on the DS and TS make me argue this complication is likely just as difficult, if not more so.