The new math dialog (T118617) introduces a change from the way the inspector works by displaying a large menu of mathematical symbols at the cost of dominating the page. Allow users to choose which way they would rather edit by showing the inspector by default and making the full dialog optional.
I think, we should not extend the number of configuration options, since that makes bug reporting and debugging difficult. So maybe we can provide one default wich works reasonably well for most useres and do not have to maintain two alternatives.
For power users hooks with custom scripts might be an option. But that's just my personal opinion.