I think that having words for this stuff will help me remember them in the longer run. For instance, the defender movments in ASU kata #2 goes (I think), "waki gamae, watershed, left-yokomen, right-yokomen-to-win"... well, the last isn't really a yokomen but I don't know the name for it.
my understanding is, you're right, it is not really a yokomen and it is even not really "to-win". I am not affiliated with ASU, but we do the same kumitachi. Saotome says in his DVD the final control is just a defined end of the kumi-tachi as we cannot continue it forever. But it is neither a win by killing, nor the partner's surrender, even if it looks fairly as if.
And the technique starts like a yokomen, but then pushes the other sword aside by twisting the sword and hitting with the side of the foremost third and then moves foreward to lead into the final control, which is clode to a tsuki, but is not aimed to kill, but only to stop the partner.
Unfortunately, I do not have the names, so yokomen-to-win or yokomen-to-finish would be appropriate names to recall the technique, as it seems to be the standard finish in Saotome sensei's kumitachi.