Ineffective lookups for Greek letters in phonetic notation

[dscorbett]

Font

NotoSans-Regular.ttf
NotoSansMono-Regular.ttf
NotoSerif-Regular.ttf

Where the font came from, and when

Site: https://github.com/googlefonts/noto-fonts/blob/4cdde035fd5138d6653a2176ba728b5b6f8cc533/phaseIII_only/hinted/ttf/NotoSans/NotoSans-Regular.ttf
Site: https://github.com/googlefonts/noto-fonts/blob/4cdde035fd5138d6653a2176ba728b5b6f8cc533/phaseIII_only/hinted/ttf/NotoSansMono/NotoSansMono-Regular.ttf
Site: https://github.com/googlefonts/noto-fonts/blob/4cdde035fd5138d6653a2176ba728b5b6f8cc533/phaseIII_only/hinted/ttf/NotoSerif/NotoSerif-Regular.ttf
Date: 2019-11-01

Font version

Version 2.003; ttfautohint (v1.8.2)

Issue

Each of these fonts has two 'locl' lookups substituting beta and chi with forms designed for phonetic notation. They have no effect: the lookups are applied for the script tag 'latn' but only apply to Greek characters. While it is possible to override the script tag (e.g. by setting the language to und-fonipa-x-hbsclatn in HarfBuzz) I don’t think any itemizer does so by default.

[moyogo]

This currently works with hb-shape but not in browsers for example.

A resolution would be to add the locl lookup to script grek.