When is it good to really start to focus on grammar?

[Amenophyckxs]

Am I hurting myself putting Genki off and focusing on WK?

Think of Japanese like a cube. In one dimension, you have speaking and listening. That’s the width of the cube. In another direction, there is grammar. That is the depth of the cube. Finally, you have the height of the cube, and that’s reading and kanji. Your ability to use Japanese is based on all three dimensions. If you prioritize one dimension over all the others, you will make progress without increasing your ability to use Japanese. BUT, and here is the big thing, you’re not hurtin…

This is a good summary imo, just exchange genki with whatever grammar source you prefer.