1. No issue reference exists in the blacklist, nor does a tracking issue.
This issue could become the latter.
(I didn't check the mailing list archives, which is where I presume the original discussion of blacklisting Blender originated.)
2. "OptiX" is not capitalised correctly in the description.
3. The package is outdated, so this next issue may go away once it is updated:
4. There are many file paths containing "cuda" or "optix", and some @.cu@ (CUDA) files which lead me to believe some remnants of support for CUDA and OptiX are not fully removed:
- @usr/share/blender/2.93/scripts/addons/cycles/source/kernel/kernel_compat_cuda.h@
- @usr/share/blender/2.93/scripts/addons/cycles/source/kernel/kernels/cuda/@
-- @usr/share/blender/2.93/scripts/addons/cycles/source/kernel/kernels/cuda/filter.cu@
-- @usr/share/blender/2.93/scripts/addons/cycles/source/kernel/kernels/cuda/kernel.cu@
-- @usr/share/blender/2.93/scripts/addons/cycles/source/kernel/kernels/cuda/kernel_config.h@
-- @usr/share/blender/2.93/scripts/addons/cycles/source/kernel/kernels/cuda/kernel_cuda_image.h@
-- @usr/share/blender/2.93/scripts/addons/cycles/source/kernel/kernels/cuda/kernel_split.cu@
- @usr/share/blender/2.93/scripts/addons/cycles/source/kernel/kernel_compat_optix.h@
- @usr/share/blender/2.93/scripts/addons/cycles/source/kernel/kernels/optix/@
-- @usr/share/blender/2.93/scripts/addons/cycles/source/kernel/kernels/optix/kernel_optix.cu@
5. Newer versions of Blender include Apple Metal support, which I think has no libre implementation and I presume is pre-disabled on non-macOS builds.
6. Newer versions of Blender include HIP support, which I think is libre, but is only implemented on Windows at the moment.



Perhaps lines 109-112 (inclusive) of the @PKGBUILD@ do not do this fully(?):
@ # libre changes
local _extra_opts=( -DWITH_CYCLES_CUDA_BINARIES=OFF \
-DWITH_CYCLES_DEVICE_CUDA=OFF \
-DWITH_CYCLES_DEVICE_OPTIX=OFF )@

I'd also like to thank @bill-auger for maintaining the package, which I suspect is quite the chore.