That’s right - I started with it when it was BitTorrent Sync before they spun it out as a separate firm.
No - all VPN’s are blocked on site. However, I get around it if I really need to by using FreeFileSync, which allows me to sync over SFTP (on Port 22) if I have to. I think that means I could tunnel traffic via SSH if I wanted to, but my Synology only has the SFTP service enabled, I’ve disabled the SSH console (and locked down the IP addresses that can connect), to try and increase the security of the NAS.
However, I very rarely need to sync to my server whilst at work - my work files are in Onedrive, Teams and Sharepoint so they all work fine.