DIY Down Half UnderQuilt

I am new to hammock forums and have been hanging for about a year so bare with me. I have recently gotten into DIY gear and caught the bug bad. Right now I am planning out a Half Underquilt, I am looking to get a similar result to the Warbonnet Yeti 3 season. I have roughly planned what I am going to do (in following pdf files) I choose 2" loft and 46" x 40" for the quilt with grossgrain channels for continuous shock cord suspension. I am hoping to get down to around 20 degrees with this and a section of my Gossamer gear Thinlight Pad under my feet.

So far it's gonna cost me as follows:
3 yards - 1.1 oz ripstop nylon DWR - $10
1 yard NoSeeUm netting - $3.25
15 ft 1" Grossgrain - $6.30
30 ft 1/8" Shock Cord - $7.50
6oz. of 850+ FP down = $46.45

With shipping it totals out to $83

Everything but the down is from DIY Gear Supply
Down is from Wildernesslogics

Tell me whatcha think! Any advice/opinions would be great!

Were you looking to make this a differential cut?

I wasn't entirely sure if I should or not. I allowed a little bit of room on the edges so that the exterior wouldn't squeeze the down too much. What would be the benefits of a differential cut?

It takes away some of the compression from rounding (fitting) the UQ to you as you lay. There are a few really good threads about it and you can look up the differential calculator that Cat Splat put together easily enough.

Here you are - CatSplat

Thanks! After inputting every thin it looks like i was pretty close I just need to make all of the outer baffle widths long as opposed to just the edges.

Looks like it will be a nice quilt. Pics when you are done?