WHBM
I disagree with you about the B747 water injection.
It was reasonably reliable and in the case of the airline I flew with remained widely used until the aircraft were replaced with RR engine new ones after about 1979 .
It was however a bit nerve racking in use ,particularly for the FE.I don't remember the engines being designated with a W. Our final ones were JT9 7Fs (from memory).
In the case of the 707s water disappeared fairly early when the JT3s were fan modified.
Wunwing