I don’t believe version 7 is being updated anymore, since SheetCam was sold. The new owner released version 8, which is a completely separate product which has no update path from version 7. So the highest revision of v7 is probably what you want to use, unless you want to purchase a whole new product with some additional features.
My understanding of a beta or development version is one that has changes that haven’t been fully tested. I don’t believe SheetCam v7 is any longer in development since the company was sold and V8 was released. Personally, I’ve always installed the latest version available, but you can do whatever you want.
If you’re concerned about the stability of a newer version, install it in a different location, so if you discover issues, it’s easy to revert of the previous version.