In November 2013 I posted this but the post is locked so I can not bump it:
If you double click a variable name in the source that is a component of a derived type, VS selects past the percent sign on the left but not that on the right! It would be better I think if it stopped for both sides. It seams to have got changed in XE2013 update 5. In update 3 select stopped on both sides.
It is not yet fixed in XE 2015 update 3 and I presume not in later ones. I know it probably seams minor but it does affect users productivity. Is there an issue number ?