We use tags for our sales pipeline (for example, New, Contacted, Invoiced, Closed, etc.). And we have different sales pipelines for different products.
The first problem is that when a stage changes, we have to remove one tag and add another one. It would be better if there was a single select option, so that when you change a stage, the previous tag is removed automatically.
The second problem is that we end up with 15+ tags for different stages in different pipelines. It would be great if we could define several single select options and use them in different cases.