I'm still new at this so.... I don't fully understand the entire theory behind 70/30 grinds but since re-turning my knives back to a 70/30 edge they are insanely sharper and feel as if they stay sharper. The video that made me understand the differences and start to look into it is

The 70/30 edge is actually ground into the blade when its made/fabricated. I found keeping the factory edge of 70/30 gives me a longer edge retention.

I reassure you the video I posted has lots of information about knife edges and different kind of knife grinds, that'll give you an awesome basic understanding behind knife edge grinds specifically japanese knives.

Hope this opens pandora's box for you