Garniture de dérivation à 5 orifices Allure 19591000

We have had this installed for less than a year and despite only probably using it 20-40 times, the plastic extension in the valve has ground down and now I am needing to replace it as it's stuck on one setting. If Grohe offered brass extensions I would buy one but unfortunately you are stuck with a plastic one. Plan to need to learn to replace it yourself (not too difficult but a pain if you have any caulking around the baseplate as it has to be scraped and redone each time. On my next build, if I use Grohe products, I'll ask to see the parts first to avoid plastic on metal like is the weak link here.