Custom Fields Reporting and Data Retention

SOLVED

Hello,

I am inheriting Sage 50 from a previous workers set-up / preferences. The needs of our business have shifted and the use of the previous custom fields is no longer needed and I would like to repurpose them. If I inactivate or change the custom field names, will it retain whatever data was previously entered per customer? I want to find the easiest way to start "Fresh".

Secondly, what is the best report to run to identify any customers with existing data in these fields? The best I could find is the customer management detail and it takes a loooooong time to load. Any suggestions would be greatly appreciated.