I can relate to that kind of relationship with Sx and So.
While the general and non-type-specific definition of So doesn't really resonate with me too much and fits as the overlooked "blind spot", the 4-specific So descriptions are a massive elephant in the room and probably always will be whether or not I use them to type again or not. For instance, I'll just drop
this here. Mostly where the social 4 has fewer "anti-shame" defenses than the other two variants, can err by being too transparent about that vulnerability (while Sp and Sx would guard themselves more), and is given to social comparison. Not so much the one about the 4 as a social critic, though if you are close enough to me that I'd trust you with my anger, I do have some...passionate...things to say about those matters.
On the other hand, Sx is a hard sell if you're just looking at my behavior. I'm far from 8-like. However, what the dissonance between Sx's meaning as a dominant instinct and my behavior would have to imply if it
were my dominant, is true and needs to be seen and dealt with. It's a little sickening to think that I've treated my needs that way, but it's a fact. While it could be easier to explain myself as a different type, the impetus then to face this habit of pushing back on my desires and real traits would be lost. As you say, I'm better served by the way I type now.
And yeah, contrary to popular images of the type, my fight with the Sx instinct precludes long-term relationships a lot more often than it draws me toward such a thing.
I guess I'm impressed by how many people here apparently don't go by behavior alone to judge type, because that was something I really struggled with while in the process of typing myself.