I plan to put kerning for Devanagari linear conjuncts into . I could do this by setting up the kern pairs in Metrics Machine, generating a feature file, and copy/pasting the kerns from it into . But that leaves me with a bunch of kerns that won’t work within Glyphs. Is there a way to do this natively inside Glyphs?

What do you mean by "kerning for Devanagari linear conjuncts into "?

For example: t-deva does not connect to ga-deva, leaving an ugly gap. Shifting ga-deva 50 units left would close the gap. So I’d like to put
post t-deva ga-deva -50;
into the opentype feature to close the gap so that it is always active. But I need to generate lots of pairs like this and right now the most convenient method of doing so seems to be generating a feature file Metrics Machine and copy/pasting the GPOS lookups into in Glyphs.

Why not just add kerning in Glyphs?

Experienced Devanagari type designers have advised me to put the kerning in because is always on when an Indic shaping system is active but kerning is not always active. Of course I’d be happy to hear contrary arguments!

Georg wanted to say that if you add “kerning” between two devanagari half-forms, this info will be put into the dist feature instead of the kern feature. It is automagic.
I only recommend to you to put some real kerning, at least once, between any non-devanagari glyphs; if in the font file there is only “kerning” between devanagari half-forms, the OT feature is going to generate an empty lookup in the kern feature, and the font won’t be generate.

Thanks, Nicolas. isn’t covered in the handbook, so I didn’t realize that Glyphs does this automatically.

And thanks to Georg for making this stuff automatic!