The next couple of versions will focus in getting reed of any existing issue, then I will resume working on this feature.
I may have found a solution to handle the charge necessary and which might not cost too much.

Once a first beta with basic subscription syncing is available I will study the impact on the servers (and the cost), then I will add more syncing step by step, in order to sync the read status, favorite flag, playback progress, …
Hopefully I’ll be able to add this feature in the free version

I should have a beta ready for testing in a couple of weeks ;)

Edit: There will be a first beta in a couple of days, with subscription synchronization only.
It will allow me to have an early on feedback before everything is implemented

I should have a beta ready for testing in a couple of weeks ;)