I sent the car back to the
dealer to have a leaking rear screen washer fixed - I emphasised that I wanted the software updated to benefit from bug fixes and enhancements, even if there was no fault. The
dealer is helpful and honest, and he told me their system does not show software updates as being available unless there is a fault code present - so they created a fault to trigger the software update.
You're 100% right that it should happen during
service (or better still, OTA) - all customers should benefit from VAG's ongoing bug-fixing and enhancement of MIB, not to mention any improvements to engine & battery management or stability / braking systems etc.!
So I now have 1898 - the only visible change I can see is the climate control UI, but I only had the car 3-4 days on 1790 so I wasn't that familiar with it!