Ability to perform a CSV import from any URL
The free CSV importer should be able to import from any publicly-accessible URL instead of having to first upload to WordPress.
Additional functionality (worth paying for in the sense that it could be only available with an Event Aggregator license) I'd like to see is the ability to set intervals for scheduling re-importing from a CSV URL.
One-time and scheduled CSVs via URL would be useful for getting data from other sites that aren't running The Events Calendar (which Event Aggregator can already handle) and for situations where a third party is providing the data to us, sometimes on regular schedule.
Additionally, just to perform my own CSV import, importing via URL (e.g. publicly-accessible link to a file from Google Drive, Dropbox, or another one of my own servers) would help keep clutter out of my Uploads.