I’m also interested in this issue. The closest thing I’ve been able to find is the idea of a ref helper, but it looks like that’s just an idea and hasn’t been implemented yet (even as a straw man). To put the issue another way, I want to write a reusable addon where sibling addons can somehow communicate DOM state to each other; these are concerns of the component and should not be exposed outside of it. Currently there’s no good way to do this (or if there is, it’s either non-obvious or I am blind).