> That can definitely be a problem in general, but is it likely to crop up in this case?
Only issue I can think of is slight loss of precision along big surfaces, as partial derivatives will have bigger deltas. It's only a problem if your fragment shader maths is numerically sensitive to such things.
It's fine for use in rendering if this is the final shape and it will never be modified. You're just a bit limited in terms of what you can do with it.
