Implications to changing SFTP Automation fields

We have a text Additional Field in our user profiles for their orgnization levels (department, division) but we found that since our HRIS has an inconsistent way of abbreviating these for employees, the informaiton does not match what we are manually entering for contractors (those that are not in the HRIS). We want to change this field to a drop down. Assuming we just add the drop down and mredo the SFTP automation mapping to that field instead of the current text field, are there any implications we are missing that we should consider? This isn’t really addressed in the help documentation. Thanks!