Localized blocks?

I'm exploring localization and I have an upcoming project that would ideally utilize localized sets of blocks. For instance, a page my contain one set of blocks for English and then another set of blocks for Spanish.

Is this supported or is it possible to support?

I'm being silly, was trying to put the localize property on a tab definition

my exact use-case does completely work. even allows you to fallback to the default language.