I've made a lot of chipotle in the Traeger over the years.
Wash, core, split, smoke until dessicated, then into the food processor. I recommend wearing a breathing filter of some sort for the last part. Neoprene gloves are good too if you have sensitive skin.
The peppers were tiny so I sliced them into small, thin circles and just laid them out in our very warm sun porch.
But there was no seed in them but a pith of some kind. Did that need to be removed? Or does it?