I have a few collaborators in my team but I would specifically like to do a 'timeline' base so I can see where a job should start and finish for me. I was wondering if it was possible to upgrade only one person in a team, not the whole team, or if I'd have to create a new, separate AirTable?
I'm afraid not; the plan is applied to the workspace and not individual people. As such, you're going to need to create a new workspace entirely and upgrade that. You can then create a base in there and use the timeline view