Thanks for the tip. It needs AOS 8, which blows it for me using my phone. Though it could motivate me to hack AOS onto a Kobo e-reader just to run Blorp.

Blorp in theory could do this. It would need a bit of tuning to really work well under the circumstances you mentioned. For example, feeds only refresh currently when you open them, but I could have it auto refresh all your subscribed feeds when you connect to the internet.

Draft posts and multi account support is already there if you wanna give that part a try. Writing comments offline wont work yet. They may save if you don't close the app before reconnecting to wifi, but I wouldn't count on that.

I'm the developer behind Blorp btw.

Not sure about creating posts but blorp can at least cache posts for offline viewing.