I’ve worked on a prototype that can definitely lift any robot, which has confirmed that this is not the challenge. The only restriction I can see for any decently thought out lifting robot is the neglegence of their partner. As long as a team designs their lift to be as versitle as possible and their partner designed their robot with the same idea in mind that is as close as you can get to universal compatibility. This is the teamwork element I think the GDC was going for when they introduced elevation.
We had a community outreach event a few nights ago and decided to bring one of our teams prototypes for lifting a robot. Its two FRC totes from last years game Recycle Rush they weigh approx. 7.8lbs. We are gonna continue to tweak it for competition season as well as a shooter.