Completed French translation

Really I don't understand your argument. A POST necessarily changes the state on the server of the target resource (this is the default behavior for HTTP). The server reports the change to clients that are querying it by HTTP "STAT" requests, and any POST request is (by default) not cachable by all conforming proxies (unless your HTTP request specifies it explicitly).

But loading the dialog doesn't change state in the server. Saving does, but that is already POST.

This is an issue of Loading the dialog which still does not perform STAT requests to validate what is currently cached in Javascript variables. In fact this is very irritating : opening any question by clicking it should always revalidate its preloaded and cached resources, but it still displays old values that have already been updated by someone else or in a separate window (for example in a search window when checking the terminology used in other "similar" resources).

This revalidation should be done to help reviewing the existing translations, including those that we have done ourself (and that disappear from the list of "untranslated messages" if we refresh the window to void the local Javascript cache variables (usd by the AJAX editor to open movable dialogs in the current window). For now the best that can be done is to force all clicks to open a new window or tab, to avoid loosing the current list.

Anyway, this is not an issue of MIFOS itself but a usability issue of TranslateWiki.