Tess: overall I think this looks good. I have one concern I'm writing up right now. This proposal says - when you create a shadow dom you can choose manual or automatic. Automatic is the status quo. New mode: you have to use an API and slot things in different places. One cited advantage of the API is implementing something like the details element. before having this feature you can't implement that feature on top of web components. One downside of the exclusivity of the two modes (man/auto) is that it's sometimes advantageous to have special behavior with some descendants but have the rest auto. My feedback is that I'd like them to make that case easier - some manual slotting and then "everything else auto". Otherwise it looks great!

Ken: I looked it and also liked it.

Tess: i will mark as pending ext feedbac

Tess: Part of the goal is that .. no slot ... imperative API lets you manually slot everything... Doesn't solve the usability issue - if you want to implement something like details .. one or two that have special slotting behaviour and rest auto - this not solved. They replied to this issue. I need to digest the response.

Dan: they said already looked at?

Tess: yes - my concern was raised years ago... can polyfill.. need to look into it more. Was nice to get a response promptly. Work in progress...

Peter: might be interesting to have a declarative way of doing this - could be as a polyfill on top of this API. A map of selectors...

Tess: that's what Shadow DOM v0 did. There were some complicated rules ... shadow dom v1 dropped that and has a model of explicit name slotting. Could be worth exploring again.

Peter: might be worth at some point revisiting the declarative... so you can build custom elements without having to write any [javascript].

bumpe