I have, on my own or in co-operation with Erik, CPU-modified a great number of lenses over the years. Must be well over 100 units by now, plus over the years I have sold more CPU kits than that for users to modify their own lenses.
As original brand new Nikon spare parts are used for the contact block, the mounting guard on the contact block is solid metal, and bespoke screws keep the components firmly in place, I have yet to see a failed modification using these kits.
The snapshot below is the outcome from one of my many trips to visit Erik. The CPU modification really makes using all those Nikkor gems from the past a breeze.
I'll have to discuss with Erik what is possible to do with the 50/1.2. Oops., he answered while I posted. Putting this on a future to-do list, then.