I managed to get my modified player to get knocked down. It looked freaking awesome. But the problem was that the getup animation didn’t trigger while enemies were beating on the player character’s body. R.I.P.
Sadly I cannot reproduce the effect as it is a very rare (bug?) occurrence that allows it after setting boss skills with knockdowns.
I guess the point of this ramble is…after seeing it, knockdowns on the player character should be implemented completely. 