From the minute I started with CND rods I've loved that rod and am amazed at the value it provides. I really love the feel of that rod and the way the line just jumps off the blank.
The line I've used the most with that rod so far is the Rio Midspey 7/8. It's a spot-on match for the way I cast. With a 13' leader and 15-20ft of running line in the hands to shoot, you're well in the 90ft range without a lot of stripping between casts. Flatten out the d-loop and bend the rod low near the handle when pushing the forward cast and it will really fly.
If you look at what the manufacturers publish for grains/length for lines, the Airflo delta 8/9 is in the same bracket so I am sure it will cast well if the ratings are correct. The Wulff 70' spey 9wt is 36.6 grams or 565 grains, also in the right range. In other words, mid-length spey lines in the mid-500 grain range will load it correctly. You can see it's not prudent to follow line weight ratings for spey lines, but grains over length is usually quite reliable.
I have yet to try some of my recent line acquisitions on that particular rod but have also fished the Windcutter 7/8/9 extensively on it and found it even rockets the 15' type 8 tip with ease and I would highly recommend the setup for sinktip use during winter run pursuit.
But your question is about longer belly dry lines, and the above paragraph is what I would recommend.
IMHO that's one of the easiest spey casting rods out there and at the price, hard to beat for what you get. No skimping on the hardware, all fuji SiC strippers and tip guide, hard chrome snakes and the traditional handle, butt and seat.
Glad you enjoy the rod, and the best part is the way it feels with a nice fish tearing up the pool!