When it comes to positioning the element, stuff we have (directional properties, media queries, transforms) and stuff that's in the works (container queries) looks like it'd pretty much accomplish what I needed.
The suggested syntax accomplished everything I needed, would be super easy to implement for the end developer, and has a track record in existing browsers.
As other use cases are added/considered my suggested syntax probably won't be all things for all people and that's why it's awesome to see everyone commenting. They have more cases from a variety of different perspectives.
If you have another use case in mind, please link it up or post it here! Ultimately, any additional flexibility the spec could give us in this area is a good thing.
When you say this it makes me think you've got a list of items with counters, tooltips, etc. I've been able to accomplish this effect with a combination of position: relative/absolute; as outlined in one of my earlier posts. If you have other use cases, please link or add them to the thread.
Hopefully that makes sense! As long as I can accomplish my simple use case I'll be happy with anything