Hi, I’m using Freshrss on a VPS too. What it’s missing to me it’s, like you, a foss app client. Because there a’re FeedMe or FocusReader that work pretty well, but they’re closed source and IIRC Chinese too.
A few weeks ago I was thinking that maybe it should be possible to sync Feeder rss across different hosts through Syncthing, but I haven’t found experiences about online, neither I’ve given a try.