Please expose absolute weight in fontconfig
Right now fontconfig uses a relative scale for weight, like it does for width.
However the OpenType and CSS specifications use an absolute scale, including for variable fonts
The unit divergence between fontconfig and the specs makes it hard for users, packagers and font makers to check if a font deviates from the standard using fontconfig tools (and every error one lets pass snowballs once enshrined in config files and documents)
Please expose an absweight parameter in fc-scan, fc-list, etc that can also be used in fontconfig files, and convert silently between weightand absweight engine side, so it does not matter which scale humans and apps use to talk to fontconfig.
(alternatively weight could be fixed to conform to the specifications, but that is a backwards-breaking change)
Fontconfig already needs to convert between those scales since the meaning of standard weights is given in an absolute scale in the specification