tl;dr; Yes for newer projects! But I'm not convinced it's worth dropping everything and re-working persona.
I love this approach. When combined with all the work we've done with cache compatibility, I think it's highly complementary to our current toolchain, and comes with zero performance impact once we've got forward proxies and eventually CDN.
The thing I like the most about it is that it makes it easier to build tests that exercise code that is currently only run upon deployment. (for instance, wouldn't it be great to exercise all of the magnification logic and run frontend tests on the minified version?)
This: "Tests can run without any rebuilding and they use the same code as the production app"
and finally deployment is faster and can always run with all locales enabled.
+1
lloyd