Lan Sao, not bong sao but Lan Sao is what you show in the above videos.
However, I agree in that bong sao movement a structure can be use in several grappling situations.
Not quite, since the main thing it allowed me to do was step in and bring my bong elbow over the top of their elbow after pushing the arm across. I bet if I look long enough, I would probably find a video of a Judoka teaching something similar as part of grip breaking. A two on one type of grip break is common, but sometimes if they have both of your sleeves, you have to get creative.Something like this?