Batch patron modification would be a logical place to include an option to renew selected accounts. Currently the account expiry date can be modified there, but that only updates the account without being an actual renewal. For libraries that don't want to automate account renewal, it would be nice to have a way to renew in batch that isn't messing with patron imports.
Our library would love to see this implemented! Our use case is school students who all expire on the same date every year, and are updated if they stay in the school system for the next year. We currently have to do this by hand if we want to register an actual renewal in the patron account.