agreed... i always find myself running the module twice because of this. Whenever I use this tool its always to edit existing fields and not create new ones.
Although it's in the "Not Planned" Status, this idea is the more general idea of having custom defaults as one way to solve this issue. Instead of changing the default for everybody, advanced users can change the default for themselves. While I can appreciate that they won't add custom defaults for every tool, perhaps they can start with low hanging fruit like the multi-field formula tool.