Line boxes contained in an inline-block element that should snap to an outer line grid are instead snapping to a line grid based on the inline-block's line-height. In the testfile, an outer line grid is set at a 30px font-size. The inline-block element has line-snap:baseline but also a font-size of 100px. The lines in the paragraph are snapping to a 100px font-size grid, when they should snap to a 30px font-size grid.
Created attachment 239367 [details] testcase
This appears to still be a problem in Safari 15.5+.
<rdar://problem/97031003>
WebKit ToT (266047@main) is still broken. Adding 'BrowserCompat' tag to monitor it since Chrome Canary 117 and Firefox Nightly 117 match each other.