I know you're not going for making powder but this might help. I developed a guide for smoke-dried chile pepper.
http://www.bbq-brethren.com/forum/album.php?albumid=323
I only burn wood in my UDS and Bandera.
If you take them off sooner they will be roasted but not charred. Charring is what you need to remove skins. If you built a good fire under a expanded metal drum (instead of propane) you would be able to accomplish your goal. of skinless roast pepper fillets.