If we were talking sailboats, I would say that there is no substitute for starting small, as in "no motor and if you screw up, you get wet" small. I started on a Sunfish, then Hobie 14, and then a Venture 24. I learned how to sail, how to depower, etc. using sail handling. When the engine on my friends Pearson 303 failed, she didn't know what to do. I said, "it has sails." She said, "but I have to a dock it in a slip." So, I sailed her boat into its slip. She was amazed. If she had started with a Sunfish, instead of a Pearson 303, she wouldn't have been amazed.
But nowadays, with all the systems, like remote control bow and stern thrusters, etc: I'm not sure that I feel the same from the RT23 through the RT31. You can start fresh with a RT31 and learn how to handle it pretty competently if you are prudent. Not so with my former single engine wooden H28 sailboat, or single engine wooden 27' Chris Craft cabin cruiser (no garmin, no thrusters, no everything else...........).
Just do yourself a favor, one you have mastered your RT27. Dock it now and then w/out using the bow thruster. That way, when it fails due to dead battery or sheared pin, you can confidently do it the old school way.