I am a family physician and heavily trained in the world of western science and healthcare (and which does NOT have all the answers). Previously I could get some sense of qi flow, mostly in hands and generating a general sense of warmth, and would tend to fade after 15-20 minutes of meditation or post training.
With your visualization training wheels, I have been amazed at the rapid passage of time in the sessions, as well as being able to get to the sense of overall pore breathing which is new and kind of amazing to me. Energy levels are good after training, but overall my life is pretty low key on stress in recent times.
Your approach to qigong and the non-doing practice makes much more sense to me than much I have read/watched on qigong and I am greatly enjoying the weekly sessions and home practice. Qi gong has shifted to a stronger role for me than the Taiji.