IDK how to think about singularities. They are the limit as t-> infinity for all infalling particles.
But t -> infinity is a long way off.

According to PBS ST, the space and time coordinate flip axes when you cross an event horizon (EH), so that means you are free to move about in time, but inexorably moving in 1 direction in space. IDK what that even means. But it makes me question if there is a sensible way to talk about distances inside an EH.

A black hole is an object whose diameter is incomprehensibly larger than its circumference. The extreme curvature of spacetime makes understanding distance a mind-bender for me.

All we know for certain about the singularities (or whatever is inside the EH's) is that when they merge, 2 EH's become 1 EH.

There is some confidence to be had that GR, which predicted EH's, can at least somewhat describe what is beyond an EH. But we cannot measure anything beyond an EH, so we cannot know for certain.