Operating system: Windows-7-6.1.7601-SP1 64 Bits
Graphics card: GeForce GTX 770/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 441.41
Broken: version: 2.83 (sub 2), branch: master, commit date: 2020-02-12 19:49, hash: rB9fe469c11094
When a rig has show_in_front enabled, it works like normal, and when Bone XRay is enabled bones show in front and work like normal.
If a rig has show_in_front enabled and Bone XRay is enabled, the bones in that rig can not be selected via mouse.
You can use python, the outliner, A (select all) but you can't select it directly using the mouse.