https://www.ebay.co.uk/itm/Creality-CR- ... SwoNpepVmY
The misalignment can catch you out if the z-axis servos get out out synch. The result is a a z-axis bar that is not parallel to the print bed with resulting bad prints, and that is a nightmare if you are doing a big print. By using the levelling blocks at the start of each print you can quickly make sure that the servos are correctly set and synched and the print starts out correctly.
It isn't necessary to buy the stls as it shouldn't be a problem to whip up a design for the level blocks or even cut them from a piece of scrap wood or whatever you have handy.
Alwyn

