Extended HTML Elements: "is", wrap up an HTML element, or anything else - What the current state?

Question

Considering we all know about the limitations/facts, I was wondering how the current state is or let's say the best practice now a days? Last time I'd checked I concluded that "wrapping up" an HTML element could be the best/safe approach instead of using the "is" attribute since it could become deprecated, but we're almost in 2021 ... any new ideas?

Answer 1

Apple (rniwa), has not changed its/his tune in the past 5 years:

We won't implement Customized Built-In Elements in WebKit

• https://github.com/WICG/webcomponents/issues/509
• https://bugs.webkit.org/show_bug.cgi?id=182671

They work great in all other Browsers.

And they are part of the standard, so I don't think they will be deprecated

• https://html.spec.whatwg.org/multipage/custom-elements.html#custom-elements-customized-builtin-example