Cloak initial string when using lazy-loading

[UnrealKazu]

When using the lazy-loading functionality, it is possible that the language file arrives after the rendering of the page has been completed (due to a slow connection, for example). This results in the temporary display of all initial strings before they are translated.

It would be great if there were some cloaking functionality for the translation directive (and filter, maybe?) which is aware of the in-flight lazy-loading call and doesn't do a translation lookup until the request has been completed. This way, the strings would just be rendered empty until the translation is ready.

How much work would it be to achieve this?