In my workflow I create different set of instances, one set is [x] save as ttf, the other one nothing, and I export as if I was only exporting OTF. So I have ttf and otf in one click.
Anyway, when I export different formats, of the same name, the app doesn’t seem to take the file format into account as a difference between two file of the same name, and raise a feature error.
Workaround so far is to name TTFs differently or save them in a different folder (with an added export folder parameter). But I have several cases when this workaround is actually quite annoying.
This is also not working for variable fonts (exporting desktop + web)
It took me a while realising the cause of the problem, as suddenly plenty errors appeared on export mentioning issues in the feature code. But it works just fine switching back to different file names on export.
