If you look carefully at the photo you can maybe make out I've just made a raised garden bed for it as I'm on a flat block that floods when we have very heavy rain and wreaks havoc on the rear part of the garden (despite the drainage i have put in).

the plheb is raised maybe 400mm.

in addition the natural soil on the land is clay. the acuminatas that sit next to it on flat ground in clay have struggled somewhat. But the acuminatas are several metres tall now despite the poor draining soil and occasional short periods of flooding. As these are easier to find I didn't have an issue putting the broad phyllode variants to the test. And after a few years it seems to have paid off. Other wise the next raised part of the garden bed in that photo is housing 2 courtiis and a narrow leaf acuminata as I wanted to give them the best chance of survival with well drained soil.