Spring Reno

My lawn is a mix of fine fescue and nzla perennial rye. I want to be able to use etho throughout the season including winter to help control foreign grass and that means killing off my fescue. I am a bit worried as i like the softness off the FF.

The plan:
Step 1: 2-3 post emergent applicatons of etho and meso 2 weeks apart over september
Step 2: Start of october heavy dethatch pull out all dead material ( FF and whatever else)
Step 3: Heavy over seed nzla perennial rye
Step 4: Pre-emergent etho and meso,
Step 5: Starter fert
Step 6: Solid etho pre emergent schedule to cover bases
Step 7: Post emergent applications for anything that sneaks through

How does that sound. I have basically never had any weeds come up only ever ugly grass most likely POA. Does this seem like a good idea and plan? Any other ideas? Is there a better way to get rid of my FF or keep it and control foreign grass? Cheers