It's just another (hopefully somewhat systematic) perspective on a known phenomenon, though. (OP here.) P.S.: What might be of minor interest is that this may

It's just another (hopefully somewhat systematic) perspective on a known phenomenon, though. (OP here.) P.S.: What might be of minor interest is that this may help decide, whether it's "ROL A" (as in older assemblers) or just "ROL", etc. (as in some of the more modern ones). We may see that there is a slot for "ROL A" and another one for "ROL implied", which is a NOP. As is the case with all the other accumulator instructions. – However, brevity is still a thing. :-)