CR10S Linear Rail - Rail blocker

I had a lot of problems with CR10S, I had to level the bed each time, then I realised that the 6 wheels of the bed are not stable, so I have changed the 6 wheels with 2 linear rails 500mm.

Then the problem was that 500mm is pefect for a CR10S lenght but the first holes do not correspond to the 2020 profile line, therefore I was forced to create a Rail blocker.