It's confusing or always needs further distinction if "UX" when discussing client-side application development is talking about developers. "DX" is useful.
OTOH, when I hear about DX of a software product (especially an open source one), my intuitive understanding is that it is experience of developers working on the product, not of developers that happen to be users of the product (which, if they are the normal users of the product, would just be UX.)
