Okay ...
I know I sad v4 was the final version but looks like I lied
I found this amazing engine sound for mid level transition and it sounds much better now along with some other fine-tuning
Updated v5 DL can be found here or in the first page
https://www.dropbox.com/s/0qwsoe0kyuzdjjh/Sound%20~~%20Mirage%20Engine%20Sound%20Tweaks%20v5%20%281.5.4%29.rar?dl=0