There is a problem in sh404 with duplicates and K2 tags and the context in which they are viewed. It's not a bug really but a problem of meaning that sh404 doesn't distinguish or simply can't

K2 tags links have contextual display when non sef / sh404
By contextual I mean the active menu Itemid and therefore, from a user point of view, the section of the site you are in.

For example:
Menu item 'publications' has an Itemid 212
http://domain/index.php?option=com_k2&view=itemlist&layout=category&task=category&id=43&Itemid=212

When you click an item tag link to a tag, eg named "Conflict" on this page, it will resolve to Itemid 212
eg: index.php?option=com_k2&view=itemlist&task=tag&tag=Conflict&Itemid=212

Menu item 'Our Work' gets an Itemid of 184
domain/index.php?option=com_k2&view=item&id=163:conservation-agriculture-project-care-sierra-leone&Itemid=184

A tag link to a tag name "Conflict" on this page will resolve to Itemid 184
eg:http://domain/index.php?option=com_k2&view=itemlist&task=tag&tag=Conflict&Itemid=184


Turn on sh404 and you only get one tag link for "conflict"
domain/tag/conflict

sh404 will store duplicates with the different context of each url above but this means sh404 is forcing you to choose one when actually bot are valid

Unfortunately this means sh404 fails to keep the context of where a K2 tag is being viewed.

One option is to turn on the menu item id append which will add an item id to the url - but this defeats the whole purpose of using a URL Manager.

Another option is to manually make specific urls for every tag in the different contexts. Eg I can take the two urls above and make custom urls like:
our-work/theme/conflict
publications/theme/conflict

To fully realise the work involved in this you can multiply the number of tags by the number of categories
So if you have 60 tags and 10 categories you can go and make 600 custom urls to deal with the issue. This is just not a sustainable option to me.

Is there another solution from the K2 side?