1. Heat sear the edge - that is a lot of linear feet with a large risk of flame up/burnt fingers. Doesn't sound like fun.
2. Hem the edges of the baffle strips - lots of straight sewing but do-able
3. Roll/hem the edge and attach to the shell in one pass. There are a couple of references to this technique (Schneiderlein) in various older threads. I think that would take some skills I don't have (especially if using shaped or curved baffles).
I take it that you only use the 8d as an inner shell because of the lesser wind resistance. I think that the breathability here would be a plus. I have 3 yards of it, but it feels so different from the 1.1 I am use to, I chickened out and went with 1.1 on my current quilt's inner shell. When you used it for the shell, did you hem the edges or just heat seal and enclose in outer channels.
How has it worked out for you? Any difficulties or downsides?
I am starting to think that the lightest bang for the buck would be M50 ($12.95/yd, 0.69oz) outer shell, 8d ($7.50/yd, 0.67 oz) inner shell and Nanoseeum ($5.99/yd, 0.7oz) for baffles. This would total ~$80 to purchase 3 yrs of each (for full length UQ).