Missing small caps in OTF releases

[mlpo]

Bug

For some reason, small caps no longer seem to be available as OpenType features in OTF releases since version 6.12 (v6.11 is fine, all subsequent versions—including the latest to date, v7.040— are not).

Evidence

This problem can easily be observed on FontDrop!:

v6.11	v7.040

[mlpo]

Just after opening this issue, I came across #434 and #482, related to Adobe products.

It seems that all these issues are duplicates (sorry for opening another new one…), although in my case the problem has nothing to do with Adobe, but with the detection of small caps by FontDrop! (using thus opentype.js).

[mlpo]

Ok, after investigating a bit, it seems that the issue is due to the presence of multiple substitutions in smcp section. These substitutions are of course necessary (cf. #303).

So I wonder if the problem is not just in the analysis of the font by FontDrop!.