!!FUZZY!! message exported?

I don't see the point. If you translate a message partially, why should it not be exported? The untranslated message will be shown untranlated as well. A partial translation is even more of a translation than the original message. Thus it is generally perferable to have a partial translated message rather than an untranslated one.

I agree that, having a second type of !!FUZZY!! string inhibiting export would add desirable flexibility.

I would prefer my draft translations into Swahili (not my native language) not to be exported before being proofread by a native speaker.

That's an unsupported use case. If you don't feel you can contribute to a locale at a sufficient level, don't.

Two contradictive experiences:

• I know sufficiently well how to translate some simple messages to Low German, but I am not used to either of the specific orthograpy systems being used by nds, and nds-NL, translators in the WMF context, so I make errors. Too many. They asked me, not to help, since spelling corrections were as much labour as typing from scratch.
• In another context, of a non-European language, I heared quie the opposite: "If we did not have that non-native computer-literate helper, who contributes the hard stuff, we were lacking half of our translations, even though we have to make many adjustments and corrections."

So I see it as a community matter, contributing stuff mainly to be revised before published may be, or may be not, a good way of workhsare. That said, I think, eiher should be supported in the best thinkable future of all.