Will the stylable <select> element be able to break outside the browser window?

[guillaumebrunerie]

I remember that an earlier version of the explainer (when it was still called <selectlist>) explicitly pointed out the fact that unlike the <select> element, <selectlist> would not be allowed to break outside the browser window. But I can't see any mention of that anymore in the current version, is the plan now to allow it?

I understand that there might be security concerns with allowing a webapp to draw arbitrary content outside of its own window, but there are definitely situations where I wish I could customize the contents of a <select> better, while still allowing it to break out of the browser window, so I hope it will be allowed in some form.