^.. and we can always learn from the future
https://www.amazon.de/U-S-S-Enterpri.../dp/1844259412
"Thanks to the info in this book and a quick trip to pep boys I had my good old constitution class running like she has just slid out of the dock at Utopia Planitia."
I guess the special innards of the Astute class's front dome are not being explained in detail. And the cover states it is "copyrighted material" so no ill-willed person will ever dare to copy it..
On topic:
The cort jet is good for effective power transfer, but it also increases cavitation already at lower speeds. The big 'brake' is of course the rudder

While the deterrence of the T-class units is still to be reckoned with, a real-time control of the GIUP gap and North sea will be impossible with so (relatively) few attack sub units.
https://en.wikipedia.org/wiki/List_o...ubmarines_(SSN)
Maybe build smaller/cheaper ones, or drone subs?