I'd say to give it a shot, because he's comfortable with his cage! Maybe taking him around the house while in his cage will allow him to grow more comfortable with other areas! However, if he doesn't like the change, put the cage back! You'll never know until you try!
Although, it would be a lot easier if you could get him accustomed to a movable playstand instead...
I might also suggest finding what *is* within his comfort zone while away from the cage, then interacting with him within this comfort zone. Once you've figured it out, you can start pushing the boundaries without taking him out of his comfort zone completely. Try and make each experience a positive one, and once comfortable, push those boundaries again!
In short, try to go at his pace, pushing just a little, but not going too far.
Although others will probably suggest taking him out of his comfort zone completely and training him away from his cage....