According to factory suggestion, the cost of software upgrade is quite high because all the sensors need be recalibrated and tested. Also considering the freight cost to and from Germany, it’s not so cost-efficient to upgrade software of a very old device.
Is it really necessary to use 4 decimal points for customer? Maybe two extra decimal points doesn’t make a lot of differences to them. Also if they still have budget, maybe they can consider a new unit with latest software version.