Per CU clock seems very odd, dont buy that, the timing and logic would be very complex. Why ?
Also he rabbits on for ages, will wait for the time stamps
If there are many many layers to a chip, the critcal ones will be the gates / transistor switches if you like. The critical smallest one will be the gate and the speed of switching, which is based on the smallest dimension but also the material used in the gates and its properties.
So when people talk about 7nm, its a density but just about, some parts will be much larger than 7nm, thats just the smallest gate and you also have to think in 3D (thickness and widths / lengths). It could also be a fancy novel gate material that works better......secret sauces all the time bt you would not also get the transistor density.
A good indicator of how advanced in nm and how much EUV is used, which will allow smaller more
consistent dimensions is the performance per watt and frequencies as well as density.
Hence we know ps5 is up there with 2.23 Ghz GPU which is impressive for such voulume parts, but also maybe PART due to the fancy cooling technology....
But you will never actually know unless AMD tell you. TSMC never will.