Solving the mono problem

In an earlier post I showed you my sink-remapping which sent audio either to my speakers or my headphones. The problem with this setup is that I needed to disable remixing, effectively muting all mono sounds (and probably screw up surround sound, haven't tried that). The solution, or rather fix, is as follows:

#mono mappings
load-module module-remap-sink sink_name=mono-spk master=sound_card channels=2 master_channel_map=front-left,front-right channel_map=mono,mono
load-module module-remap-sink sink_name=mono-head master=sound_card channels=2 master_channel_map=rear-left,rear-right channel_map=mono,mono

This lets me hear audio from mono sources by sending them to these upmixing sinks.

The two drawbacks with this solution is that I have to switch sink manually and applications playing both mono and stereo will still be muted for either mono or stereo (although I haven't used any such application)

I did try to remix the sinks without success:

load-module module-combine sink_name=speakers-comb slaves=speakers,mono-spk channels=2 channel_map=front-left,front-right

If anyone got this working, please tell me how :)