So I took the Filament Sample Card from https://www.thingiverse.com/thing:2997350 and wrote a script to generate .scad files based on entries in a CSV.
I also wrote a crappy bash script to process them on the CLI with OpenSCAD to drop STLs, but that's still a work in progress.
./generator.rb
This will read filaments.csv and dump out a directory structure like BRAND/MATERIAL/BRAND_COLOR.scad
then you run process.sh which will iterate through all the .scad files and put STLs.
Then you slice and print as normal. Each card takes ~40minutes at 0.15mm layer heights on my MK3S.