I haven’t seen any reason to be suspicious of Cube Audio. I had a good experience with them and the distributor when I needed to swap out a driver shortly after receiving the Nenuphars.
just a couple words about that: changing the drivers is easy in principle but it can be tricky to execute. The magnets are very heavy. I found it best if you lay the speaker on its side before beginning surgery. Obviously you want to do that on a soft rug. Once you remove the bolts (ONLY the four outer hex bolts, the inner ones hold the spider together), the driver can slip from its position suddenly. If you’re close to the floor you have more leverage on the driver and a shorter way for it to fall if something bad happens.
Also, the magnets are so powerful that they can easily pull a hex wrench from your fingers when you loosen your grip even just a bit. The wrench will fly directly on to the edges of your whizzer cones with quite a bit of force. The simple answer is a non-magnetic hex wrench (believe its 4mm). I found one for 12 bucks on line and thought it was a small price to pay for the peace of mind.