I guess that is fair. Most of my non-Android computers use U-Boot. One is some UEFI implementation. I don't know how it copes with growing the ESP. I don't see why it would freak, though.
Many of us have been burned by making the assumption that UEFI implementations behave sensibly. Most of the pain points have been ironed out by now, yes, but the lesson I've taken away is: don't assume.
