I think it could be possible that i'm a sx/sp rather than a sp/sx just a really repressed one and i don't like the idea of identifying as a sx dom so i tried to say i was a sp/sx instead for a long time.
Like an octopus, honestly. (I'm speaking for myself.) Sx/sp is syn-flow (moving toward... I don't know, I like the syn-flow/contra-flow theory because it does help me type people) and 9 wants to merge with its environment in some way. With the 1 wing, under stress criticism and demands can be placed on the object of desire for the sake of merging fully and comfortably. But I don't think this necessarily has to mean another person... It can also be wanting to have music playing at just the right volume with just the right degree of intensity to evoke just the right feeling...just as an example. It could be wanting to be in a natural environment of the perfect temperature with the most strikingly beautiful view or tactile feel, etc. as another. But obviously, most intense are going to be the feelings toward the other person, and if you can't merge with the other perfectly, rage or despair could escalate into criticism, and at worst, a nasty see-saw pattern of criticism and then idealization and then back again.
...But I guess when you're relatively healthier it would be more like wanting to merge with the other...whether that's a person or nature or something else...but you can still relax in the face of boundaries, and just be comfortable wherever you are and appreciate that moment... I consider myself a relatively unhealthy 9w1 sx/sp, though, to be honest with you.