System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce RTX 2070 SUPER/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 457.51

Blender Version
Broken: version: 2.91.0, branch: master, commit date: 2020-11-25 08:34, hash: rB0f45cab862b8

Short description of error
In sculpt mode SHIFT+R shortcut doen't respect the Unit system and Length
As you can see in the attached image the value is still displayed in meters, while on the remesh tab is correctly displayed as centimeters.
This can cause problem when working on objects smaller than 1 meter, in fact to get enough resolution we have to scale down the voxel size to 0,0x or even 0,00x values, which are hard to control using the shift+r shortcut.

Exact steps for others to reproduce the error
In a new file set a different type of Unit System or even unit length to see the incosistentcy,