Only just a new idea (maybe someone else had the same, I do not know) to make it a bit more professional, we made this new combination of Output flange including the "fixed" guibo.
Ok, it was necessary to modify the prop shaft again (same flange as on the LSD side), but it works perfect :-)
Here the old variant with fixed guibo, the problem was, you have to buy the output flange at BMW (it is a well known problem with damaged teeth at the 235 gearbox) , plus producing the aluminium guibo. Now the costs are reduced to EUR 250.- for the complete part (in hardened steel). And there is only 1 part without any additional screw.
W.