Hi,
another very simple way to handle the "non-WB" ones, should you prefer to use some:

- eventually remove the WB version from corresponding folder opened using CB-Emu (to make clear the one you like is not there)

- create a small batch file to directly launch from MessExtra - for instance in the CB-Emu directory, create a "Mephisto II.bat" file including
@echo off
cd MessExtra
start MessExtra mephisto2

that's all... adapt the "mephisto2" sample parameter according to the device you want to launch... then you may organize your chess links, including one to CB-Emu.exe and a few ones for the directly accessed MessExtra emulations, linked to your .bat (or .cmd) files.

Grüße,
Eric