"If royalty feel the distinction is no longer important, I am sure I can rattle on about British law before the term existed!"

Fair dos if you want to post something that is historically inaccurate then it is your right to do so. It is equally one's right to point out inaccuracies though!

The UK government were taken to the civil court in Scotland in the 1950s over the monarch's numeral. The govt used the argument of parliamentary sovereignty but that argument was thrown out - however they won the case because the ruling declared that the monarch's numeral was a personal matter for the monarch. In other words she can call herself what she wants. The palace has since stated that the numerals used would be the highest available. Hence theoreticaly if we had a King Alexander he would be Alexander IV even though only Scotland has previously had King Alexanders. The chancs of the palace actually putting itself in that situation again are probably small.

What the monarch's style themselves doesn't always match reality. Edward I wasn't the first English monarch called Edward. James VI of Scotland styled himself King of Great Britain over 100 years before Great Britain existed as a kingdom. Likewise if you ever visit Traquair House you can see numerous portraits of the 17thC Stuart monarchs in which they style themselves not only Kings of Scotland, England and Ireland - but also of France.