If command line operations can be done directly, it is also possible to read avs by pipe.
I use avs2pipemod, but avs2yuv, etc. would work as well.
avs2pipemod64 -y4mp input.mkv | "C:\Program Files\Topaz Labs LLC\Topaz Video AI\ffmpeg" -y -color_primaries 1 -color_trc 1 -colorspace 1 -color_range tv -i pipe: -sws_flags spline+accurate_rnd+full_chroma_int -filter_complex tvai_up=device=-2:model=prob-3:scale=2:compression=0.24:details=0.24:blur=0:noise=0.12:halo=0:preblur=0,scale=w=3840:h=2160:out_color_matrix=bt709 -color_primaries 1 -color_trc 1 -colorspace 1 -color_range tv -an -c:v prores_ks -profile:v 3 -vendor apl0 -pix_fmt yuv422p10le output.mov
The GUI is still unreliable due to the long history of color space processing problems (BT601, BT709), so I stick to the CLI 
