Is this a recommended approach? The charts are amazing and I'd love to just wire up both a grid and chart to one store and have them interact w/ each other.

One issue I've found is that when a grid column header is sorted, the pie chart will redraw itself. This isn't exactly ideal since slice colors and order changes. So it's a bit misleading since a user may think the data has changed when it has only been sorted.

Can this behavior be disabled or worked-around?

Check here for an example: Just sort some columns and notice the pie chart changing every time.