A t iny hint not for 9,000 miles but if you aggregate points and are at NN,900 or so:

Rewe sometimes has attractive bonus offers for Payback points - their normal accrual rate 2 Euro turnover -> 1 Payback point is crap.

But this week a product with a long used-by-date is available:
https://www.rewe.de/payback/

Elmex/Meridol toothpase with the multiplier 30 x.

As others already mentioned points post within some days and then can be transferred with a minimum of 200 Payback points.

Last time I stacked up some Barilla pasta products. (Offer changes week by week).