So, this is a bit specific, but might come up for other people.
A few of my feeds are from https://www.comic-rocket.com/ 's archive binge feature. Every day at X time, it takes the next ten comics from the archive and adds them to the RSS feed.
This means I get an RSS update with ten new items, where the item order is important, but the timestamp is (or is nearly) the same second. Currently newsblur doesn’t keep the ordering (I’ve no idea what the ordering it’s doing is, it doesn’t seem to be predictable).