Focal / JMlab inverted tweeter with ferrofluid?

Good evening,

I just bought a pair of JMlab/Focal DB30 speakers with inverted tweeter and decayed foam ring. Now is the foam ring not a problem I guess. And this JMlab, some older Kevlar tweeters shall be without Ferro fluid.

But now comes the real question. A friend of mine bought a - not that old - Avalon speakers with.. Focal inverted tweeters. I heard these speakers (2-way) and like to buy these to. Now the 1 million dollar question: Does anybody knows if there are Focal/JMlab inverted tweeters (with foam ring) made with Ferro fluid? This because Ferro fluid might dry up, and placing of a new foam ring in the future might give problems.

Thanks in advance for your response,

Best regards,
Edwin