That is exactly the way Kanetsuka Sensei does nikyo ura - not surprising, given who his first teacher was…
All the Aikikai Hombu shihan I have come across, as well as Saito Sensei, tend to bring the hand into the shoulder to deliver the pin, even from shomenuchi and yokomenuchi. Kanetsuka Sensei's argument for not doing this (except where the attack is a shoulder grab in the first place) is that when the attacker has a weapon it is quite dangerous to bring that hand straight into the body.
Oh, and his nikyo is extremely effective, without inflicting much pain at all. The sensation is more of being knocked to the ground by a blow to the whole body simultaneously.
Just to disagree - If there were no pain, uke
would not move, except to stop his wrist breaking. I think we get used to the pain and so think there is none. The danger is to kid yourself as to the reality. Sometimes, when I 'hear' or 'see' people teaching stuff, I just want to get up and ... eer ...show them how wrong they are. But alas, I am too polite.