Transferring from this issue #370 (comment)

The Bulgarian Minister of e-Government Bozhidar Bojanov has launched an initiative for Bulgarian institutions to use fonts that support Bulgarian Cyrillic. Source: https://www.facebook.com/bozhidar.bozhanov/posts/pfbid036YFX1SuEjFv4Mzg4WGfdnmCSG6yKT5f4wBokqjZigxCER6tkFdmrxzsD6xeedLBzl

The IBM Plex font is widely used in the Bulgarian web and I suggest you add support for the Bulgarian Cyrillic Script so that everyone can take advantage of it. You can read more about the loclBGR glyphs with examples and info on this article - https://www.lettersoup.de/what-shall-be-done-for-bulgarian-cyrillic-loclbgr/. More detailed information can be found here - https://www.fontfabric.com/blog/rounded-bulgarian-cyrillic-narrative-and-comparison/.

I will be more than grateful if you consider my proposal!