Perhaps there is a complication that I am not seeing….
There is no way to force the algorithms to function in mono. The architecture relies on which cables are connected to the outputs in order to determine whether the effects function in mono or stereo.
It also seems like the user could achieve this capability in Insert mode by treating the pre-amp in the amplifier as one “insert” and still have room for one more. But with this method the user would have to be very careful with the routing options.
That is correct. Insert Mode also allows for pre/post mode operation and also gives a user an extra insert to play with. The danger lies in making sure you don’t accidentally close the entire loop by bypassing an insert, but it otherwise works well.