Surface inspector H/V shift discrepancies after rotating or flipping

[gooball60]

To reproduce:

• Select a brush face and set the H/V shift to a specific number, say 16 for H and 48 for V.
• Rotate/flip the brush once or several times, notice how the shift values may be one or two units off from the original (17 instead of 16, 46 instead of 48). Can be aggravating when rotating a group of brushes since many of the textures get slightly misaligned.

[Garux]

I'v tried to reproduce w/o luck. This requires straight guide one how to reproduce, possibly with example map.
Note, that, if you transform with texture lock on, it's alright for values to change.
Other thing to note, transforms use snapped origin, so brush can migrate slightly (uneven ongrid square brush dimension after two flips, for example).
The textures get slightly misaligned issue also depends on exact case; guesses: 1.doing w/o texture lock 2.doing for nonaxial faces: this radiant only supports old axial projection mapformat, which is limited in texture locking possibilities.