Can I use two Otto and use them as both multiples and trunks?
For example input 1 normalized both to 2,3,4 on the same module and (1),2,3,4 on a second Otto module (that does not have anything connected to input 1) ?
Yes, you can!
Use two Otto Passive Mono and connect them according to the drawing above.
Each Otto Passive Mono comes with a female header where tip 1-4 and tip 5-8 already are connected as two separate groups.
Use these female header on both Ottos.
Then you just need to solder a shielded cable over from Otto1 to Otto2 according to the drawing.
Use female headers or female dupont cables to make the connections to the Otto pins. You can take a female to female dupont cable and cut in in two halves. Solder the halves to your shielded cable and hide the soldering with shrink tubing.