I’m glad you are finding TftUA helpful.
With a small spread between AeT and AnT like you have you will do next to no training in Z2. It is too fast. Doing much in Z2 will be a fast way to become overtrained. The fitter you are the more polarized your training intensity needs to be. In your case you will see the best gains by doing your aerobic base training in Z1 and adding more time in Z3 and Z4 to your training plan. Avoid Z2 unless it is a specific long tempo session where you plan to have a recovery day or two afterward.
I hope that helps.