V-Core 3.1 400 with bent X-Gantry?

Hi, I set up my first self-built printer today. Most of the time I spent on getting a reasonable mesh. After I had no success with changes to the frame and everything looked the same, I temporarily placed paper under the X-Gantry, and it worked... That doesn't look too bad? Now the question arises whether I should replace the X-Gantry or use shims? What do you think? Thanks and regards