They do have free cloud sync. It's capped based on the frequency of updating files rather than on a particular file size.
> Your notes will always be stored locally on your paper tablet, but only files used and synced online in the last 50 days will continue to be stored in the cloud and updated in our apps.
> Your notes will always be stored locally on your paper tablet, but only files used and synced online in the last 50 days will continue to be stored in the cloud and updated in our apps.