I typically want to download only over WiFi. But sometimes, like when I'm traveling and might not have reliable WiFi, I still want to keep high-priority podcasts up to date. It would be nice if I could override my default network setting for specific podcasts only to allow syncing via mobile data, especially if it were coupled with a qualifier like "if not synced within X hours," so that it would automatically go into effect of I haven't been able to sync via WiFi recently.