Quite confused as I’m worried about ruining the current deck progress/algo, do I simply redownload (unsubscribe & then resubscribe) the anking deck from ankihub and open it in anki again?
Hello,
I would be happy to help. 
AnkiHub is designed to allow you to update without interfering with progress, so you should be good there. If you’re concerned, you can always make a backup first, just to be safe.
In order to make a backup, from your top menu bar in Anki: File - Create Backup
Aside from that though, subscribing and/or updating your deck shouldn’t interfere with your review progress at all. Please let me know if that answers your question, and if there’s anything else I can help with.