printarenas is a script - it walks through all your arenas at each offset. You could craft another script that remembers the last arena and offset you successfully transferred and only send those after that.
I think there is a pattern where you can save the last arena,offset in the local fossil. Then you could mount the remote venti to check that last arena,offset that actually arrived and stuck to the disk on the remote site. On a similar subject I have 10 years of backups from a decomissioned work server that I need to merge into my home venti one of these days... -Steve
