Weird… it doesn’t do that in my setup (Using Blender 3.1.2) - is it possible one of the plugins you are using is somehow “reserving” that attribute name?
File above has been updated to support curves and profiles with 2 points…
The fix has kindly been provided by @Zebrahead
Previously when either the curve or the profile consisted of a 2-point curve, then the node-group will not produce the correct results. This has been fixed.
Many thanks to Zebrahead for finding the issue and providing the fix!
With version 3 the caps were not taking into account the radius of the points so I added a capture attribute to get the radius to scale the instances of the caps
The issue is that the UV output was in Point Attribute Domain… it needs to be using the Face-Corner Attribute Domain… Same goes for the CapMask. You can also use Named Attributes instead of the Group output but you also need to remember to use the Face-Corner Domain.