You are going to need to explain more clearly or better yet, diagram this.
For example, do you have Romex or other conductors? If you have Romex, it’s easier to describe and understand. If you don’t have Romex, then we have to struggle with individual conductors. I’ll presume you have Romex for now.
in Box 1, you have a line . . got that. Is there a 3-wire running from Box 1 to the Smoke Detector box? (Just describe the wiring you have. i.e. “Traveler set” doesn’t describe the number of conductors running between the boxes.
Is there a 3-wire running from Box 2 to Box 3?
What type of switches are in the box?
What are the connections at the smoke detector box? I have no idea what the random traveler is that you reference.
So see if this makes sense. If need be I can diagram.
You are basically going to use this drawing for an understanding of what you’re doing, but it’s going to be modified to account for the ceiling box:
The Inovelli goes in Box 1. The incoming hot and neutral on the 2-wire go to the Line and Neutral terminals on the dimmer.
For the 3-wire going to the Ceiling box, you will be doing 2 things, sending a neutral and traveler for the Auxs and sending the load. So still in Box 1, connect the black of the 3-wire to the Load on the Inovelli. Connect the white to the Neutral on the Inovelli and the red to the Traveler on the Inovelli.
So now in the ceiling box, you have a Load, Traveler and Neutral coming in on the 3-wire from Box 1. Connect the black on the incoming 3-wire to the black on the 2-wire Load Romex. Pigtail the white on the incoming 3-wire with the white on the Load Romex and the white on the outgoing 3-wire. Connect the two reds together. You won’t be using the black on the outgoing 3-wire, so cap it off. So what you did here is send the switched hot to the load w/neutral and passed a neutral and traveler to the next box for the Aux.
In the next 2 boxes, 2 and 3, connect the red to the Traveler and the white to the Neutral. You won’t be using the black conductor here, so cap it off.
I switched config settings 21 (Neutral) and 22 (3-way toggle) on, and the aux switches are now responding from Box 2 & 3. When I go back to Box 1 though, the inovelli isn’t responding. The aux switches also work the same on both sides (press up on, press up off) Is there another config setting i need to look at to get everything working right?