"Interesting. I remember reading that ocean water is higher near
underwater mountain tops due to increased gravitational attraction and
measurable from satellites,"

The would be one hell of a dense mountain to do that, I would think it more likely to be because of a decreased gravitational pull being forced away from the center of mass of the planet, due to its inverse square relationship. But that is not my field of expertise. (is anything ? the more I learn the less I know, if it weren't for learning from mistakes I would be a babbling idiot - NO COMMENTS FROM THE PEANUT GALLERY HERE !)

"I wonder if tanks could be designed with non-flat bottoms to counteract what you mentioned"

Pretty sure that would not work because gravity is the leveling force. As such the shape of the bottom should not matter.

Perhaps at a high altitude with a very large mass (dense, not voluminous) placed under the center of the tank it could be compensated. But then that makes splitting hairs look like hitting the broad side of a barn with a planet.