Potassium has to be supplemented when the growth is forming, that's the problem... A rothschildianum spike will deplete a lot of potassium from the growth.
As for the parentage, out of it, we see it has Mt Millais in the ancestry actually, that's the dorsal to expect on its progeny, as well as the synsepalum.
So far New Horizon x Raptor as parents does match...
For the potassium, yes that's the problem with plants from Hawaii, I saw that posted a lot of time around on Facebook. The problem, you can barely reload potassium when it is too late, but you can keep the plant from decaying.
Sometimes it is so agressive that the cells completely leak, and it looks like a kind of bacterial rot. Most of the time, the leaves become yellow, then orange/brown quite quickly, from the bottom. It looks like a disease but it is absolutely not.
Another symptom is that plants tend to bloom on single growths without new start. then they take years to restart.
I suspect they use a heavy urea feed to push the plants, the same as some Taiwanese nurseries. This explains too the very large leafspan vs. root system commonly seen...