it is always fun to sit on the sidelines watching a 'battle of quotes and sources'. It is good scholarship to be sure that you are not just looking for reasons to justify what you simply want to believe. That is sort of like throwing the dart, then drawing the bulls eye.It is my observation that Bruce O.works harder than about anyone I've seen to sort out the truth of the matter-and I have no doubt that if anyone presents hard facts that contradict his position, he will be be the first to acknowlege them.
In the matter at hand, if 'union' preceded 'elbow' as a common name for the pipes, it makes no difference whether "Uillean" is a good name or not (even though it actually is). Pipers will probably always continue to call them 'Uillean', and with good reason, but it just may be that they were called 'union' first.