According to the text of 2.6 in the Rules of UEB, if "your" is preceded or followed by the line continuation indicator, then the word is *not* standing alone. This is because no part of 2.6 in the Rules of UEB allows for the line continuation indicator. In other words, to the best of our understanding, because the line continuation indicator is not currently explicitly identified as something that allows a word to be standing alone, a word before or after a line continuation indicator is not standing alone.
This is a very fine rule distinction, so it is unlikely that contracting "your" would mislead the reader. But, as I said above, according to a very close reading of the rule as it is written today, the line continuation indicator would prevent the use of the shortform "yr" in your example.