So here is a little update on my prints:
At first an adjustable hand reamer sounded like a great idea but the fact i don’t own one and they are like min 25€ I gave up on this idea.
My simple solution than was that i scaled the corner blocks,feets and the cornerblock lock up by 2.5%. Now those parts fit nicely.
The joiners and rollers however fit perfekt printed at the original size.