[ftinspect] Wrong PostScript shown with MM/GX fonts.

ref !37 (merged) :

There is a subtle difference between selecting a named instance and selecting the corresponding, identical axis coordinate tuple with the Variation API: The instance's PostScript name can differ. For example, if you take NotoSansCJK-VF.ttc and select face index 3 ('Noto Sans CJK TC'), named instance index 2 ('DemiLight'), the PostScript name becomes 'NotoSansCJKtc-DemiLight' – this value is stored in the named instance structure. If you manually select the corresponding 'wght' axis value 350, however, the PostScript name becomes 'NotoSansCJKTC_350wght', which FreeType constructs following the Adobe algorithm described in Technical Note #5902.