For a Canon 7D with a Zeiss CP.2 50mm, extra support is generally not necessary. A 2 lb prime lens is within the kind of load a semi-pro DSLR mount is expected to handle, and it’s comparable to other heavy still-photo primes that do not use tripod collars.

The key issue isn’t just weight, but torque on the mount: weight combined with how far the lens’s center of gravity sits from the camera. A short, dense prime puts much less stress on the mount than a long telephoto of the same weight.

As a rule of thumb, lens support becomes more important with longer/heavier lenses or when the lens includes its own tripod foot or handle—then you should support the lens and let the camera hang from it, not the other way around.

So: for normal use on a 7D, this lens should be fine mounted directly. Just avoid putting extra strain on the setup, such as carrying a tripod-mounted camera over your shoulder with the whole rig bouncing around.