It would be helpful to get the attributes shown in the account form when performing a manual account assignment ( List users -> Add account ) for visual verification of outbound mappings.
I realize that these are not available on the fly, so there could be a 2 step process
1) Hit "save" -> get the attribute values calculated
2) Overview and change as needed.
3) Hit "submit" -> provision the account to the resource with the given values.
Sorry if this sounds too generic, I haven't had the time to dive in the code so that I can offer a much more concrete suggestion.