Huh, what does the M20A have to do with the 3ZR, aside from bore and stroke? The M20A, like the other TNGA engines, is a clean sheet design. It's not "derived from" the 3ZR. The M20A is physically smaller and lighter than the 2ZR, not even talking about the 3ZR. There are fundamental differences between the M20A and 3ZR, like dramatically different compression ratios, thermal efficiency, different valve angles, among many other things.
Nowhere did I say the M20A uses a carried over block from 3ZR. The only thing I said is that they are the same 'engine class' per Toyota's definition.
And indeed the 3ZR was one of the precursors to the M20A as it tested the optimal stroke/bore ratio (1.21:1) for the Dynamic Force family, which is a key parameter to Dynamic Force's exceptional thermal efficiency. The 3ZR-FAE had similar efficiency as the 6AR-FSE despite missing direct injection and Miller cycle operation. But just because I mentioned this particular fact does not I mean I'm downplaying the many other specific details.
And yes I've read all the published information on Dynamic Force, and non-public domain info as well. I'm not the kind of person who makes assumptions without educating myself first. I don't understand how you got frustrated by that comment.