after gathering some info and adapting a technique someone else used, here's what I did to get it to work on my G705:
Step 1. Change CDA and re-flash
Use this as customize_upgrade.xml and upload to tpa/preset/custom using a2uploader:
then run SEUS and choose to re-install anyway if it says you have up-to-date software already, let it flash. This step is necessary to ensure your phone has the latest Western Europe generic firmware, since it includes the threaded SMS. (Conversations)<?xml version="1.0" encoding="utf-8"?>
turn on your G705, make sure all is well.
Step 2. Enable Conversations view
Unfortunately the threaded view is hidden, even though it's there and ready to use. Here's how to enable it.
use this as customize_upgrade.xml and upload it:
Turn on your phone, reboot, and you'll have Conversations view.<?xml version="1.0" encoding="UTF-8"?>