It's interesting that you raise this, because I don't think the white dropper in ACR is great either.
However, it's not the LR picker functionality that I yearn for - instead, I wish you could right-click with the tool, like you can with the eyedropper in Photoshop, and choose your sample size. In Photoshop, you can choose to sample a single pixel, or an average of the surrounding 9, 25, 121, etc pixels. This would be so good to have in the raw programs. Even better than the functionality you've referenced here.
I'm rambling. The answer is "no", sorry.