I think you missed the last picture I put on my post. Ichigo compares his constantly released zanpakutou to Kenpachi's, and that's all the evidence we need at the moment.

And you can't compare Kenpachi's situation to the "laws" as how they've been explained in Bleach, he's a unique character with unique circumstances. His zanpakutou is constantly released, now is he drawing the full power of that shikai? No, because he doesn't know the name of it. Just like Ichigo could use getsuga tenshou without knowing the name of Zangetsu, given it wasn't as powerful as when he finally learned the name and could actually control it.