17 inch winter bikes from Leon Cupra 5F ST 4drive on Leon VZ310 – has anyone tried this yet?

Hello, slowly the winter comes and I would like to mount the existing winter bikes. This is Borbet T1 in 7J X 17H2 ET40 with 650kg wheel load. According to my information are the original summer rims (see my pictures) in 8J X 19 ET49. The 17″ rims should therefore fit easily from the free-access and the roll-off circumference (see here: tire calculator). I would then have made to the TÜV and just a single acceptance. The brake also has “only” 340mm, just like with our So theoretically everything fits. But practical???? So my question: Has anyone ever tried to mount 17″ rims of you on the Cupra Leon KL 4drive VZ310? Best regards, Thilo