* When getting campaign changes with CustomerSyncService, CustomerChangeData->CampaignChangeData->changedFeeds field is never set even there were changes to the feeds. However, I can get those feed changes by setting feedIds in the Selector object and checking for changes in CustomerChangeData->FeedChangeData.
* If I set both campaignIds and feedIds in CustomerSyncSelector object, I always get an empty response. Why can't I get both campaign and feed changes at once? Why do I have to do two requests?