I was going to wait a bit longer before I posted anything, but since you asked, I received my custom sleeves for my CL2's on Tuesday and have been doing some listening tests with them to try to give some impressions for the thread.
I had been looking into trying to make my own in CAD and get them 3D printed, but I kept running into roadblocks. By pure chance I came across a company from Boulder at RMAF that does custom earplugs, and also works with another company (either Final Audio or an associate of theirs) to make IEM ear sleeves.
I gave them my CL2's for a couple of weeks so they could be scanned, and they took ear impressions at RMAF to be scanned as well so everything could be matched up properly.
The fit is perfect, it just took some getting used to having the sleeves go that far in my ear. It takes a few tries to get the process down for insertion/removal, but it gets to be simple.
They are 3D printed from silicone and are easy to clean with some warm water and a Q-Tip.
As for sound, they do sound very good, but I am definitely noticing differences from my SpinFits. With the SpinFits I do not hear the 4k hump others do (I am guessing because of how large my ear canals are), but with these I am hearing some kind of mid bump, I think because of how far the sleeves reach into my ears, negating the natural size/shape of my canals. There is still great low end extension, but the mid bump is negating some of the high end extension I think. For some this may not be a big deal because they have already negated the mid issues via EQ.
The sound is not bad, just enough of a difference to be noticeable.
I am going to reach out to the company to see if there are any alterations that can be done to shorten the pieces, or adjust the bore diameter for any frequency adjustments.
If anyone is interested, the company is E.A.R. Inc in Boulder, CO. You would just send them some ear impressions and they build off of that, which takes around 2 weeks after receipt of impressions (now that they have scan files from my CL2's). They gave me a coupon code for $20 off to share, so if you are interested PM me and I can give it to you.
If you have any questions let me know.