For autocomplete, what about sticking with a department/team/issue format: e.g., Discovery-Search-BadWeight.. or they could all get a personal "_Tag" prefix: _Tag-dcausse-search-badweight. That's super unwieldy, but avoids autocomplete collisions for everything else.
However, it sounds like we could consider ignoring the "no tracking tasks" directive, at least within Discovery. (Now I am advocating going against the advice given since no one seems to be advocating for it.)