@Giggiux Not sure what you mean. If you move a topic from one category to another, it disappears from the first category. I was suggesting the capability to have the same topic listed under multiple categories.
I suspect there will be a lot of customized stuff that we end up with when we actually do the import (though to be fair, while I think NodeBB is our leading candidate, it's not a done deal yet). We did a partial import from CS to Discourse, so a lot of the user deconfliction has already been worked through.
Most of what we do seems to be non-traditional.