Unfortunately, I have a custom local.l10n.xml that changes the words
used for cross-references. I suppose I can just add this directly to
en.xml instead of my customization layer so that I can take advantage
of this speed boost. I'll report back when I get around to it. I am
very happy to see these changes!
All modification should be backward compatible so you can definitively
use local.l10n.xml. However speedup when using local.l10n.xml is little
bit smaller, but still should be quite significant.