[aur-general] masqmail 0.3 with no backward compatibility

Hello, I am currently maintaining the masqmail package in aur. masqmail is a small mail transfer agent. Last week a new version 0.3.0 was released which has no compatibility to the 0.2 branch. The masqmail developer recommends users who already use masqmail to stick with the 0.2 branch and new users to take the 0.3 branch. To make that possible there needs to be a package for each branch in the aur. I'm not sure how I should handle that. I was thinking about creating a second package "masqmail-0.3" in addition to the currently existing package "masqmail". I wasn't able to find anything about such issues in the packaging guidelines. Are there any suggestions how this should be handled? Thanks, matou