[NTG-context] [ibmplex setup script]

At present the ibmplexmonothin font is seen by the mtxrun script mtxrun --script fonts --list --all --pattern=ibmplexmonothin* identifier familyname fontname filename subfont instances ibmplexmonothin ibmplexmono ibmplexmonothin /home/vm/.local/share/fonts/Unknown Vendor/OpenType/IBM Plex Mono/IBM_Plex_Mono_Thin.otf ibmplexmonothinitalic ibmplexmono ibmplexmonothinitalic /home/vm/.local/share/fonts/Unknown Vendor/OpenType/IBM Plex Mono/IBM_Plex_Mono_Thin_Italic.otf But I don't manage to get the monothin variants loaded. Any hints available? Thanks .Floris