The one I got from you produced 1 rhizome that reached about 1ft in length, but it looks like that has stopped, but I suspect that there will be another boost of rhizome growth once that small rhizome gets filled up with starches. It's already viable, and enough for me to take observations so I think that's enough for me because it doesn't take me much effort to throw it in the tarp pile with the rest of the potted bamboos for the winter.
I have observed that it is behaving clearly different from moso bicolor in that it appears to have the ability to shoot sooner, but doesn't fire off shoots quite as easily as the clumping moso seedlings I've been accustomed to. It should successfully send a few good culms next year.
It's tough to tell from these pictures, but my ensetes are getting up to the 3ft range with super thick stems in the 5 inch range which is still nothing compared to my neighbor who has it up to 8-9ft with massive trunks. Since you have an indoor greenhouse, if your ensete is much bigger than the ones I have, it may be OK to take a pie cutting off the main plant for propagation, and still have enough time to get the piece to callus over to produce pups without taking away that much progress from the mother plant.

