I think we're talking about the same thing. Essentially - taking ukemi from shihonage by "doing the limbo." The first part of your body to make contact is your outstretched arm followed by your upper back/shoulder blade. Your butt never hits.
Can any Yoshi guys out there explain why the shihonage ukemi is sometimes practiced this way?
That video you posted is interesting. I'm not a fan of doing that for shihonage. But that is basically the first stage for a type of kick-up ukemi, which is like used for direct irimi and the like.