Ian (from the Chrome team) has suggested -webkit-line-clamp for Interop 2022: https://github.com/web-platform-tests/interop-2022/issues/16
Essentially, the proposal is to move -webkit-line-clamp closer to line-clamp and the current spec: https://drafts.csswg.org/css-overflow-3/#propdef--webkit-line-clamp (where the value is none | <integer>), and assuming we only care about behaviour when the box with -webkit-line-clamp also has overflow: hidden (i.e., to exclude the spec'd behaviour about discarding the content beyond the clamp).
Ian outlines three things in the issue:
1. RTL support,
2. Create a block-flow box instead of a flex box,
3. Support -webkit-line-clamp: none.
See https://wpt.fyi/results/css/css-overflow?label=master&label=experimental&aligned&q=webkit-line-clamp for current test results; from the GitHub issue it seems like 008, 029, and maybe 024 need updated to match the spec.
Note that I did just mark this as depending on most of our open bugs for -webkit-line-clamp; I didn't actually audit these beyond very briefly looking at titles and seeing if they looked like dupes.