Beautiful model, great details. The STL file requires some work to get good results. PrusaSlicer identifies open edges that need to be fixed. The bottom of the cross does not fully touch the baseplate. I removed 0.3 mm to have full contact. Such a large piece tends to pull away at the edges so I added helper disks for good adhesion. And lastly, I added a triangular negative volume near the top, at the base of the cross to act as a nail recess to mount on the wall.

Very well designed

Great file, thank you