Polaris currently (as of 7.8) offers some limited customization of which fields in the patron registration form in Leap are required to save a record.

When the "Name on ID" fields were introduced several releases ago (7.2?) we were excited. However, the way the feature was implemented meant that the primary name fields were now the "preferred name" fields and were required to be filled out in order to save a record. However, a record could be saved without recording a name on ID.

Our broader city government did not like us dropping the requirement to capture patrons' legal names, and we use a collection agency, which complicates things. It wasn't workable for us to save patron records without capturing name on ID, but with those fields set up as secondary, we knew it would happen if they couldn't be made a required field. We ended up developing a nightmarish workaround involving using the WebAdmin tool to customize language strings and swap the field labels around, not using the feature as intended.

All this could have been avoided if we had the option in sysadmin settings to select which fields must be required before a record can be saved. It seems like there are a lot of other use cases for this enhancement also. For example, a library might want to ensure that a patron was not registered without supplying an email address if they only support email notifications.