Create and switch WindowServer sessions with SkyLight private functions (no need for Fast User Switching, hooray!!!), compile with `cc xxx.c -g -o xxx -framework Carbon -undefined dynamic_lookup`.

SkyLight_private_newloginsession.c

#include <stdio.h>
int SLSCreateLoginSession(int *outSession); //courtesy of NUIKit/CGSInternal

int main(){
	int outsession;
	int ret = SLSCreateLoginSession(&outsession); 
	printf("login session created: %d\n",outsession);
	return ret;
}

SkyLight_private_switchtosessionbyid.c

#include <stdlib.h>
int SLSSessionSwitchToSessionID(int); // original discovery by dumping EXT symbols of SkyLight and trial&error

int main(int argc, char** argv){
	return SLSSessionSwitchToSessionID(atoi(argv[1]));
}

Tested pass on Ventura 13.4 22F66