When adding a many to many relationship or multiple one to many relationships where both sides of the relationship have the same parent table, you have to add the first relationship, then rename in the table editor, then add the second relationship and rename again in the table editor (if applicable). It would save time being able to edit the names of any new fields at the time of adding the relationship.
The same is relevant when there are multiple foreign-keys from the same parent table into a child table, and it is necessary to rolename the foreign-key field-name(s) to keep them distinct.
When adding a foreign key from one table to another in TMS Data Modeler, can the "Add relationship" dialog please allow editing of the field-name for the new field(s) to avoid these extra steps?