Will they, for example, work with my Beocenter 9500 or Beomaster 4500, with two-way remote?
Sadly no.
I tried my MCP5500 with my BC9500 several years ago. Although some of the simple functions work (source selection etc), the two-way IR seems incompatible, hence important stuff like volume control will not work correctly.
What was wrong with the BL5000s that you tried? Other than the common screen failure, capacitors can fail which stops the two-way IR from working.
