The last time you will use a Crap wheel as a PPL is the PPL exams. The last time you will ever use it as a wannabee ATPL is the ATPL exams. You will never use it in reasl life. Airline pilots don't even do there own flight planninbg it is done by ground ops. You just get in, press the same buttons and fly the same old routes, waiting to spring into action and do the good stuff if the !!!! hits the fan.
The CRP computer is a piece of history that should be dumped in the compost of aviation history. I don't believe anyone can safely operate a GA aircraft auto pilot or not and operate the CRP. It is a device that takes a lot of heads in time. Time that you should be looking out the window and carrying out see and avoid. The ASA electronic verision is marginally faster to operate but the same comments still apply. This is the reason why we have so many rules of thumb. Safety first.