Hi,

I have converted my FFCP to DuetWifi, a few years ago (2017), and the results are great.
The printer is super quiet now, and overall the performance are great.
I love using the Duet, I think its the best upgrade you can make to a 3d printer.

I am using E3D Hemera extruder, but you can also use the original extruder.

Why do you consider to replace the original PSU? I am using the original MeanWell 350[W]

You can search the forum for posts about the converting FFCP to use DuetWifi.
here is one result:
https://forum.duet3d.com/topic/3553/converting-a-flashforge-creator-pro-to-use-duet/5