Sorry, meant to reply to you with what the icon looks like on Tahoe but I added it as a reply to my post. Oops.

So making the already smaller icon still smaller that what's seen on pre-Tahoe macs doesn't seem to me to be an answer. And for the colors, what you are seeing is the result of several day of tweaking all the settings in Icon Composer to get it close to the original. There were many failures on the path to what I finally got, most of which were caused by changing settings inside Icon Composer. Only by turning off just about everything did I get to where I did.

Sorry for the late reply. I've run dwarfdump on all the dSYM files in the build directory and there are no errors. I don't believe there is anything changing the ModuleCache directory. The build is pretty straightforward. I am embedding Widgets and Intent UIs but I do the same on the iPhone version and there are no problems with that. Which reminds me, this is an iPad-only app if that makes a difference.

I'm sorry to report that it did not work for me either.