My formal suggestions are as follows
1. Open up a forum-wide poll on using the tag plug-in with the option to: A - Turn on the plug-in permanently, B - Turn on the plug-in, but only when someone complains to an admin/mod, C - Keep the status quo
2. If we decide for Option A or Option B, implement a statute of limitations to stop people complaining about tags that were posted years ago, based on the date of the most recent post in the thread. Maybe 1yr ago max.
3. Enforce the old rule about no personal abuse in tags - delete them, warn posters, or whatever