Ideally I think you might want to break it down a bit more granular.
For example…
More front end (Grip)… But at what turns and at what stages of the turn(s) will influence the change(s) you try.
I’d consider an axle a majorish change. Ideally you will have tried a couple of hubs first if you have some available.
What to change first really depends on how the kart is behaving, where that behavior is happening and how everything is setup already.
Maybe we could to a list of possible changes from mild to wild in terms of impact?
While it might seem odd given the question is about OTK… I’ll ask anyway… Have you read CRG’s handling manual? It’s worth a read. It’s listed here along with some others:
The most important thing I’ve found with karting is that there are really very few rules other than the willingness to experiment, often in ways that defy logic and “just work”.