Having these testable dummies would remove these variables thus creating a good 'control', which I feel would be helpful for those players who want to simply gauge relative damage on different gear, as well as those players who want to get more fine-grained and flesh out formulas. It makes testing things much more convenient.
The 6-line (isn't it 8-line max?) limit could be resolved by applying the right filters, depending on what you want to test, but yeah I agree that the limited line this is a hurdle. Also, it is probably safe to mention that a number of players make this a non-issue by using parsers.
