the tree is Ficus benjamina. and i want a good idea how to transport a clipping or something small to continue its legacy at my new location

Ficus Benjamina roots in water easily, so I'd do two things. Take a few cuttings. Wrap in damp spangum moss, newspaper, put in a ziplock, and send them to your new address.

Then try your airline trick with the damp sponge. I brought home some sourdough starter in a baggie in a shoe packed in my luggage. Not sure I'd risk bringing living stuff like that in a carry-on.

Now this might seem like a bad idea, but when fig trees get cut all the way back, they often grow a whole new tree later on. Just wondering if you could dig up a hefty bit of the root, wrap it in a damp towel placed in a shopping bag, put that in a small bit of luggage, and fly it with you as baggage.

Never tried this myself, but maybe somebody else had experience with transplanting just the roots. Anybody?

The professionals here must know if this would work. I'm expecting to get laughed at on this one.

Why not air-layer some branches -plant it into a small pot and ship to where you are going. provided you have the time to do that may be 6 weeks.