the AFM specs in:

• https://adobe-type-tools.github.io/font-tech-notes/pdfs/5004.AFM_Spec.pdf

require to be able to process "array" properties, for:

• BlendAxisTypes
• BlendDesignPositions
• BlendDesignMap
• WeightVector

examples:

BlendAxisType [ /Weight /Width /OpticalSize ]
BlendDesignPositions [[.5 .5] [0 0] [0 1] [1 0] [1 1]]
BlendDesignMap [[[200 0] [900 1]] [[200 0] [800 1] [[6 0] [24 0.5] [72 1]]]

we should probably implement those (even if they seem to not be required to properly parse the set of AFM files I had on my TDS)