The default behavior for the export News RSS is to take all news items, there is no problem from your side concerning this. Advanced filtering for feeds/RSS (
Upon feeds creation, users will be able to apply filtering by category, tag and other relevant fields (author, date, etc.)) is scheduled for implementation in Sitefinity 4.2 Please consult our Roadmap
for more details.
All the best,
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items