The voltages aspect is likely that the voltages are derived by interrogating the ECU's rather than directly reading from the socket, others may be able to confirm that & I would not be concerned by it
Re firmware in ECU's, BMW are not always forthcoming to Dealers on what firmware updates are actually doing but they can be improvements & bug fixes to program code or market specific data, coding & diagnostics capability etc, see the OSV, FSV, MCV, values in the autoscan
History has shown an update can transform a bike with better starting hot or cold & improve engine response at different rpm's etc. Too often Dealers were told dont update unless the owner complains re a specific problem so in general terms updating is worthwhile, it looks like on BMS-KP there are a couple of updates for your K72 model, I cant comment on the other ECU's