If you're not going to make your paint feature natural or useful, then you could provide allowable suggestions. Suggestions such as, " Paint in clipping paths not allowed, convert to paint group now," then you would click yes or no to convert. Instead, you have created an information loop Where your customers have a problem, you acknowledge the problem, and send your customers on their way to find their own solutions to solve that problem. A problem you have created in the first place. This would be a very helpful feature for you to add.