Your fsType flag for embedding permissions is currently set to 4: Preview & Print by default by default which places restrictions on editing after embedding the font in a PDF. In libre/open-source fonts, the fsType flag is typically set to 0: Installable which effectively means there are no embedding restrictions.
Also, the created/modified dates in your head table seem to have been mistakenly not set to current date.
In fonthx library this parameters seems to be here https://github.com/FontStruct/fonthx/blob/6a20967672710db5dec3a49fefe0921494c5c2... to set installable https://github.com/FontStruct/fonthx/blob/6a20967672710db5dec3a49fefe0921494c5c2...
And here both created and modified
https://github.com/FontStruct/fonthx/blob/0eb6c5932831f3ee0c4f52e27d351ba37c0b74...
https://github.com/FontStruct/fonthx/blob/0eb6c5932831f3ee0c4f52e27d351ba37c0b74...
Also it will be great if user can set font weight in your editor usWeightClass in fonthx