Operating system: windows 10 64 bit
Graphics card: Radeon R9 200
Blender 2.81 official
Broken: (example: 2.80, edbf15d3c044, master, 2018-11-28, as found on the splash screen)
Removing the sculpt level switcher makes multirez modifier pretty much useless... There is no way to go lower and work on larger forms, the adjust finer detail in higher levels. Also makes the buttons like delete higher useless as you are always working on the highers subdiv level.
Also the preview and render switchers doesn't work as soon as you do some sculpting changes on high subdiv level - like 5 you can't see the mesh at lower subdiv levels...
Exact steps for others to reproduce the error
create a uv sphere, add multi rez modifier, press subdivide 3-4 times, sculpt something. Then try going lower rez ...