One nitpick: the blocks we're talking about aren't really
low and
high, they're
low and
mid-height. But I know the blocks you're talking about.
Steps 25 and 26. Most often I see those called Augmented Low Blocks (
kodureo arae makgi).
You can find names for all the techniques for all the Taegeuk/Palgwae/Yudanja forms on the wiki.
Palgwae Oh Jang (I diagram the forms using Poomsae Designer as I learn them...which is why the Chang Hon forms probably won't ever get diagrammed by me...maybe someday some ITF-type will tackle that project!)