Shouldn't --symbols all with a specified --glyph-file include all but only glyphs specified in the glyph file? (font).
chafa --color-space din99d --symbols all --glyph-file /pr/Fonts/fonted/Blapinus3ChafaSet-12.pcf.gz -w 6 --size $(tput cols)
Seems to give me a lot of glyphs not extant in said font
Sample font:
Blapinus3ChafaSet-12.pcf.gz
Font for terminal (I may have made mistakes, if anyone finds any, let me know)
Blapinus3Medium-12-12.pcf.gz