Talk about a major lesson in frustration where a teammate goes LD and is forced outside, and there is no way for them to return to your instance. Then having to restart the STF, losing almost an hour's worth of time.
This has been a major pain since the STFs were first introduced and it's gotten even more frustrating.
You really need to fix this instancing problem when it comes to groups.
I think this is mainly in Khitomer. In Infected, Cure you can beam out, and still be able to beam back into the instance. With Khitomer (ground part), if you beam out, you will beam back in to the beginning and have to fight the cubes/spheres again.