<slot> has been around for a while in Web Components; the relevant feature here is probably the (much newer) shadowrootmode attribute: https://caniuse.com/?sear

<slot> has been around for a while in Web Components; the relevant feature here is probably the (much newer) shadowrootmode attribute: https://caniuse.com/?search=shadowrootmode https://caniuse.com/?search=shadowrootmode But you can already do a lot with regular streaming and using CSS Grid, inline <script> tags, etc to move stuff around the page.