plate quenching is quenching by taking the blade at above critical and sandwiching it between two plates of material. If he material can dissipate the heat fast enough to get you past the "nose" of cooling quickly enough, you have full hardness.
In that, it's not much different from an oil bath quench. You may or may not end up with a better quench- a more consistent and total conversion- but it's going to be at least as good.
Main advantages to a maker seem to be about the same as the main advantages to Gillette - which apparently mechanized the process for mass production of razor blades.
1: cleaner operation. (no oil all over the place, no flare ups)
2: skipping the interrupted quench phase for ensuring trueness of blades - note that this and the plate quenching method is only being applied to flat profile blades, it's ot something I can do on a forged and full convex ground 5160 bush beater. Or the warthog!
3: ensuring the trueness, especially in thinner materials, of blades as quenched. Now, you still need to normalize and make sure that the steel "wants" to be straight, especially is doing a differential temper.
This is combined with the profile only pre grinds, so that you have full contact with the plates for the quench (instead of leaving the edge dangling in the gaps)
So, there may or may not be any advantage in terms of the performance of the steel. The primary advantage lies in reducing the number of days it takes to put 12-16 blades through a profiling, heat treating, and edge grinding process. Like, potentially, from 5 or 6 to 1 long day for the main part and another day for the edge grinds.
Doesn't cut down on the handle and finishing work, and certainly doesn't cut down on the sheath work (unless you have waterjet or pattern cut profiled blades and machined handles so that a model of knife is identical from one to the next. I don't do that) - but it could keep my time on the regular leuku, LBK woodsman, and smaller EDC blades down enough to not feel such a need to bump prices to keep the family going. I'd rather pull out 5 leuku bushcrafters in a week at $160-$175 each (handles still matter in this) than push 3 at $225. I like getting the knives out to people