Should accesskit use Box<str>?

[PoignardAzur]

A lot of accesskit APIs end up using Box<str> as their string type, which is not very idiomatic for Rust.

As far as I can tell, the reason is to save space in the PropertyValue enum. But that enum also has a few variants that are as large or larger than a String, meaning storing a Box<str> doesn't actually save space:

• NodeIdVec has a Vec.
• The Rect variant holds 4 f64
• CustomActionVec has a Vec.

Should these variants be boxed? As far as I can tell every other type is two pointers long at most.