Thanks for the heads up!
It appears that my share of trouble is not done yet... I can't seem to be able to update to v4.0 - whether by a sync with Connect, running "Web Updater", or even copying the v4.0 gcd file directly to the watch.
The watch does prompts me to update, and after selecting "Install Now" it shows "Installing System Software Update", then reboots - but the version remains 3.0. (e.g., Menu->Setting->About" shows "Software Version 3.00". Also, none of the new menu items described on the V4.0 release notes are visible).
Once I get it sorted out - I will definitely give it a try. Just to be certain - I assume your suggestion is to copy the patched "5x plus" file after the upgrade to v4.0, and before carrying on with the procedure suggested - right?