Sebastian Stehle

I kind of agree, but for me the value is even too small to implement it. If you have a look to the CSS support in browsers, you will see,...

For me it is not that important.

Its not that important. I guess the challenging part is to implement all the selectors, but for me speed is more important and it is only important for very old...

One of the last missing features has been implemented :)

Where do you see it here? https://github.com/mjmlio/mjml/blob/master/packages/mjml-column/src/index.js#L298

Probably. But then tests might fail...

Will be fixed as soon as the mjml bug is fixed: https://github.com/mjmlio/mjml/issues/2684

Should already be fixed.

Not sure, We use a lot of modern features. It is probably possible but you will not achieve the same performance. PRs are welcome

I have no plans to work on this myself. If you need it you have to provide a PR.