Does the position in which you mount an IMU matter?
If the axes of measurement don't line up with the axes of motion, then comparing the IMU outputs to vehicle-relative (VR) coordinates will require some vector arithmetic to convert one to the other. It can be done, but requires some engineering time to code it and processor time to run.

It wasn't clear to me at a quick read whether your chosen IMU can do the coordinate translation itself, or your MCU has to do it. In either case, the computation will always reduce the accuracy of the original data, maybe a lot, maybe inconsequential, but expect some degradation.

Bottom line is: if you can line them up, things get simpler.