[support] Is there a way to "lock" taxonomy selections for a node after publication?

[Neil: esl-lounge.com]

I have many OG group node content types where both the URL and the title are created automatically from the taxonomy settings. 

So when a user creates a new group and selects the location to be USA >> Texas >> Dallas:
Title: My Group (Texas, Dallas, USA)
URL /group/usa/texas/dallas/mygroup

Is there a way for me to prevent that group administrator/creator from going back and changing the taxonomy terms a year down the line and therefore changing both the title and, more importantly, the URL with all its implications for SEO, site organisation, broken links, etc.??

How can I "lock" taxonomy on publication? Is that doable?

Regards

Neil
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