I believe 4D Ocean #2 is the most common model for a 3-spherical planet
If my 1st year physics did not go too rusty
Assuming our planet is 3-spherical and isotropic, that is, each piece of the planet has the same mass and the masses are uniformly distributed, thus by Newton's Law of Gravitation, the same magnitude of gravitational force Fg is exerted onto each mass towards the centre
Also assuming our planet has its rotational energy equalized, thus it is in isoclinic rotation (i.e. Clifford rotation with the orthogonal planes rotating at the same rate, so that circles were traced out instead of spirals
Fluid pressure is caused when the fluid particles is pushing against another, if particles in the bottom layer get stacked by those on the top layer, then the bottom layer experience a larger force per unit area, or pressure
Now, zooming in a small patch of the 4D ocean, you will see that in general Fg is contributed by two components, the centripetal force in the xy plane and the centripetal force in the zw plane. What we feel as weight is the reaction force we felt exerted by the object we are standing on, thus will feel heavier if there is less contribution to make Fg since gravity contributed most of it in order to give the same Fg and this gravity pushes us against the ground more (because the ground is in our way of falling towards the centre), thus the reaction force we felt increases.
As we dive deeper towards the centre in the xy or zw plane, the xy or zw contribution becomes smaller thus we felt a greater reaction force, thus the water pressure increases as we move towards one of the circular 'poles' (xy or zw) so that we only felt one of the two rotations from the isoclinic rotation.
So in general, the pressure increases as we diver deeper towards the centre of each rotational plane. Thus a depth which is closer to the centre of the planet definitely will experienced higher water pressure, but in addition, just diving towards one of the poles
while maintaining your altitude will also increases water pressure, thus 4D oceans in general works with two pressure gradients, despite gravity only acts along a single direction (down)
For 5D, since the isoclinic rotation axis becomes a line (latrix), the pressure behavior is sort of a fusion between 3D and the 4D case. Not only you have the double pressure gradients like in 4D, but the 'poles' fatten up into clifford tori since one of these circles don't rotate, this they cannot create an extra component of the centripetal force
And I suspect in 5-balls (6D) you have triple pressure gradients, given you can set up an isoclinic rotation with 3 orthogonal planes