The benefit of core XY is that you don’t have a heavy motor riding on the X-axis allowing you to push higher speeds without increasing the rigidity of the y-axis. The downside is the long belt which will stretch a tiny bit meaning a lower accuracy.

With core XZ you don’t gain anything as the z-axis is generally not high dynamic meaning the weight doesn’t matter at all but still need to eat the downside of a long belt. In my opinion, it is just a stupid gimmick people fell for because is looks novel or cool.

Also core XZ is a bed slinger. With small objects, this is not an issue. The higher they are and the less rigid the print is the bigger the issue of the 3D print itself deflecting gets. With the usual 20cm height and the usual helmet and the like this aspect doesn’t matter at all.