It'd be nice if we could remove this / replace with a stripped down layout.

E.g. for things which have -webkit-line-clamp, have a layout which just does that inlines.

Crazy thought would be to run the existing flexbox layout in addition to this (in canary say) and increase the usecounter if there are differences.

If impossible / a lot of work, just having detailed usecounts of all of the properties should be sufficient.

Additionally having a usecounter for when we have something like:
display: flexbox;
display: -webkit-box;

would be nice.