sometime after the American Civil War, I was told that even clicking on the default column mappings was like lighting a match in a gunpowder warehouse (we had lots of them back then). I believe it's more stable and not such a bad thing now, but the best practice, as I approach it, is to use custom datasources\import rules, or CMDB rules to change data that needs to be added or changed in the database.
In your case, if you want to change an abbreviation to a full word, CMDB rules sound like a perfect fit.