A weight-bearing device and being able to walk don't always go together. Tipping over because it's so difficult to balance with tight, weak muscles was my biggest challenge. It took me about 10 months after surgery before I could walk somewhat normally in public without crutches, and I got the frames off after 5 months due to doing LON.
I think I remember Salamehfix as being a half-ring Ilizarov-style fixator, which means it'll be lighter and more comfortable than the big frames I wore, but also less stable. You'd be able to move eaiser than I could, but your bones might come out of alignment easier.
There's no way I could've done LL without a caretaker. With Salamehfix you might. Of the two patients I knew who lengthened in Serbia with a monorail tibia fixator, which is even less invasive, one hired a helper to come by regularly to do chores for him and the other didn't. But the independent one was a really, really tough and resilient guy.
So be careful that you don't get stuck in a bad situation with nobody to take care of you, because that could happen.