Huge problems in diagonal letters | wght 100 | wdth 25 | opsz 48

Around `opsz` 48, diagonal letters like `YVWvw` exhibit serious problems. They are visible in the `wdth` range 25-50 and `wght` range 100-150.

https://user-images.githubusercontent.com/519108/159825933-88c71dcc-3bee-411b-a493-15b5240c066d.mp4

Start by reproducing the issue around opsz 48, using wdth 25–50 and wght 100–150, and inspect the linked video for the reported YVWvw diagonal-letter defects. Done means those glyphs render correctly throughout the reported axis ranges; the issue names no files or tests, so the relevant font source and validation workflow must first be located.

Written by the indexing model from the issue text.