Maintype 10 latest version export font as ttf but older version exportd as otf.. please fix this issue..we love otf
The font file extension is irrelevant, see:
https://www.high-logic.com/font-editor/fontcreator/tutorials/the-difference-between-truetype-and-opentype-fonts
The file extension serves as a convenient way to distinguish between fonts with OpenType features, and older fonts that lack them.
It would be better if MainType could use the appropriate extension depending on the presence or absence of OpenType features.
I thought that is already how it works.
From the OP, that is how it used to work, but in my test Cankama OpenType was exported as Cankama Regular.ttf. Old fonts like Bitstream Aldine BT that have no OT features are also exported with a TTF extension.
I think cff based are saved with .otf extension. We will look into it and add a note to the user manual.
MainType 10 will use the .ttf extension with fonts containing TrueType based outlines and .otf with fonts containing CFF based outlines. We will make a notice in the user manual.