The first paragraph seemed to be setting up for a rather different topic. I'm not sure the rest of the post says much that wasn't said in the last blog post about grid vs ToM.
My main concern with the agnostic approach is that ToM-compatible mechanics are a strict subset of grid-compatible mechanics, so an "agnostic" design is really just a ToM design. I like the features in 4E that basically require a grid to use properly. An agnostic design simply couldn't include those kinds of features.
The grid-focused stuff could be a module, I suppose. It would be pretty tricky, I think, and the blog post didn't talk about having a grid-based module.