1)
It appears that copying Smart Glyphs and Smart Components from one font to another doesn’t work properly.
What we tried (among other workflows):
– Make a List Filter from the candidates we want to copy from one .glyphs file to another.
– Use that List Filter in the target file to generate the (empty) glyphs.
– Copy and Special Paste to the traget file with »All Data« selected.
Once or twice we could find the Smart Glyph Settings copied, when only tried to Paste Special a single glyph. It wasn’t reliable though, in most cases the settings did not get copied. Also, the settings in the Smart Glyph are never ever present. Even worse and weirder: you cannot even access the Smart Component as such. Where in the source file you can just select it and hit that »Smart« button, in the target file that button is gone.
All glyphs themselves get copied,_part.xyz as well as the glyphs that use them. But the components are all over the place and not editable.
2)
Another thing related to Paste Special: If the target glyph already got some layers and content, it does not remove any additional layers when »All Data« is selected. It overwrites the Layers with the same name (e.g. »Regular«). But extra layers (e.g. »Regular 2017-01-21«) are still there. Is that on purpose? I’d expect to plainly overwrite everything in that case. »All Data« implies to copy exactly that one glyph with all and everything it’s got on the glyph level.