In this thread you deemed that a lifting robot can touch (not attach, grasp or grapple) the field perimeter and still count as a lifted robot (even high elevated). and that this ruling only is talking about the robot being lifted.
Actually, it sounds like the robot in question in the thread you linked was the robot doing the lifting (emphasis mine):
Noting the definition of a High Elevation per the Nothing But Net Game Manual (emphasis mine):
These requirements only apply to the robot that is being lifted. Thus, my interpretation is that the robot that lifts can use the field perimeter to help prevent instability when it lifts its partner so long as it is still in compliance with <SG14>:
I think the definition of a Low Elevation is also important to mention here (emphasis mine):
Criteria 3 and 4 for a low elevation are not identical with the criteria for a high elevation. I believe this means that you if you have lifted a robot above 12", but that robot is touching, but not supported by the field perimeter, you’ll still receive the low elevation (but no high elevation).
In short, if a lifted robot is touching the field perimeter, it can never receive a high elevation. However, it may still be able to receive a low elevation. The robot that’s doing the lifting can brace itself against the field perimeter (i.e., keep itself from tipping over) as long as it is done in a legal manner (see <SG14>, above).