Good work. My one suggestion would be that you make your easy workouts easier. Instead of having a lot of time in z2 and z3 most of the time should be spent in z1.
There is very little to be gained by training in z2 instead of z1. The major difference is z2 is significantly more tiring. I think you will find if you make your easy days mostly z1 then you will be able to train more and you will be able to get more out of your interval days.
Keep up the good work.