No way to do it straight from the GUI. If you get the OCC web terminal plugin, you could use a command to get recognize to scan for new files. Properly configured notify_push and cron jobs should get Recognize going within 10-15 minutes after a new file upload, but it depends on what else is in the queue and the server's processing power. The initial runs need to finish before any of this is relevant, though.

Once you get everything ingested and the initial classifications and clustering done, the process runs pretty quickly as you upload new photos.