On the other hand, it is also madness to continue building boats such that it takes twelve years between cutting steel and going on sea trials.
As explained here previously the production rate is designed not to build subs quickly or most economically but, (post the debacle caused by the hiatus between Trafagar/Valiant when most design and experienced construction staff retired or were laid off), to ensure a low production rate in order to keep the teams together until the next class was required.
Now, especially at RR who now have to increase their production rate to accommodate the Australian SSN-A reactor modules as well as RN orders, that production rate has to be revisited - as does the size of the production facilities and engineering manning levels.
That introduces several problems. The time and cost of building new/larger production facilities; ensuring subcontractors are able to do the same to ensure no bottlenecks - and assurances they'll get future orders at the same rate to justify/calculate their costs and prices; recruiting, security clearing and training the new staff such as exotic welders (which means pulling the experienced current workers off the line to become instructors) plus the RN recruiting and training the officers and men to crew them.
That's assuming the Treasury is actually able/willing to foot the bills when the full costs become apparent.....