After nothing worked out I tried ObservableHQ (based on the nice D3.js) but ...
if such a tool doesn't allow interpreting a basic two-dimensional .csv matrix correctly w/o RTFM, then your targeted user group isn't either academics of humanities nor graphic design
. So I feeling like a dumbass again
, it's back to Excel for fucks sake or in the end, time permitting, I do it all manually in Illustrator.