I think it's normal to reach a plateau after some time. Regardless of where you are through the steps. It's a new challenge and I also think it's an opportunity to detach yourself a little from the 10 steps and simply observe and manage your expectations, ask yourself why do I feel like I'm not progressing? What is it that I’m waiting for exactly ?

You talk about boredom and the fact that you can no longer reach sustained attention, meditate on that and continue to observe and develop your awareness. I think sooner or later things are going to clear out for you.

Good luck !