Currently, you have extremely limited options when choosing the default metrics to display in conversion reports:
"Default metrics show up in all Conversion reports upon login, or until a new set of metrics are selected. Only one report suite's Default Metrics can be updated at a time. This tool does not guarantee the order of events listed below. The order in which default metrics are selected may not be the order in which they are shown after being saved."
I think that the following changes could make the feature a lot more powerful for everyone:
1) It should be possible to update more than 1 reportsuite metrics in a single action (like all other report settings in the admin console!!!)
2) All metrics available for the selected report suites should be available for selections, which means:
adding calculated metrics as an option (always nice to be able to display AOV or conversion rate by default...)
adding the Unique Visitors metrics (for some reasons, at the moment Visits can be selected but not Unique Visitors...)
3) Most importantly, it should be possible to select the display order of the metrics... Not having that option is more than annoying, it makes the whole feature quite useless as it makes no sense to display the metrics in a random order (which also impacts the sorting metrics as it takes the 1st display metric to sort the data, though you DO NOT CONTROL which display metrics comes first.....)
These 3 updates would make the Default metrics option a very useful feature, as the current limitations are unfortunately too important to make it used by many.