Pannier frames don't need TÜV-approval (yet). Panniers do IF they can't be removed without tools. So, in the latter case you don't have them mounted when going to the TÜV.
I always have to change a few things before I go for the TÜV inspection every 2 years. ;-) The cops don't care, as long as your tyres are legal, etc. My bike doesn't spend much time in Germany anyway.
Other than that, once your bike is outside Germany nobody knows or cares about tech inspections, like the TÜV.
Salut from Southern France, the bikers' paradise,