There have been Animegao Kigurumi threads in CGL before.
1. The heads certainly are props
2. Many of the heads are hand made.
3. A lot of the costumes are either hand made or altered from what can be bought commercially.
4. Kigurumi performers show up at Anime events just like a lot of CGL fashions, so we are certainly talking about the same conventions.
As the readme file says.
/cgl/ is a board for the following: • Cosplay • Lolita • J-fashion • Conventions & gatherings • Sewing & prop-making • Craftsmanship tools/materials & tutorials
So it is Cosplay and if bitching about quality is not Craftmanship what is?