I’m in a similar situation and posted a similar question. I’m wondering if it’s going to work for my generation loss mkii or deco v2 as mono->stereo pedals. I’m running a voodoo lab Hex for my mono pedals into the ml10x and as far as I know, I need a mono to stereo pedal to make this transition. If I do so, do I leave it out of the ml10x or include it and run stereo? I was under the impression the ml10x needed trs inputs. Or am I misremembering something?
If you include the mono to stereo pedal you will need to make it first in any preset in which you are trying to go true stereo out. You’ll also need to use advanced mode for all of those presets.
I recommend using a pedal between your mono switcher and ML10X and going dual mono into the ML10X. You can use something as simple as a 1 to 2 splitter. It can even be passive if you have a buffer or active pedal anywhere upstream (before) the splitter (which you almost certainly will).
This way you will have the flexibility of two channels to work with in every preset instead of having to split one channel in every preset.