I do not think specifically visual imagination is a major component of most people’s sexual fantasies.
I am not denying that that is how it (subjectively) works for you. You are, by your own account, both a vivid visual imager (according to your introspective reports) and a good spatial problem solver. However, it is possible (and, seemingly, quite common) to be either one without being the other.
Well I can imagine some sounds and vaguely how touches might feel like… (though I’ve never tried imagining touch) that’s about it for me.