According to SpaceX themselves [0], the axial acceleration can reach up to 6g, though they do say it can be throttled, so what can be achieved in practice remains to be seen. Some graph on reddit with no other context is hard for me to trust.
The link I provided sources the data from an actual Starship flight. Just cause it's hosted on Reddit doesn't change the data. The link you provided was put together before flights even started from simulations.
[0] https://www.spacex.com/media/starship_users_guide_v1.pdf