I tried this on my side and cannot reproduce this.
I created a simple Configurator panel and then export and open it in Photoshop CS6.
Then I new a Photoshop file and added about 15 layers to this file.
After I keeping the Configurator panel open, I tried to switch between those layers and there is no obvious lag there.
Are you facing this kind problem with a special Configurator panel or each Configurator panel?
If it is a special one, could you please share your panel with us for a further investigation?
You can send your panel (the .gpc file and the corresponding .assests folder) to email@example.com
BTW, is it fine to ask for a photoshop panel with lots of layers of yours to us ?
I'm getting this same issue on two different Windows 8 machines with Photoshop CS6 with any panel I create in Configurator 3... Also, this same issue happens, for example, with a panel I didn't create, the HTML Sample Panel from Adobe, downloaded from the Adobe Exchange Panel.
When you don't have the panel open from start, click between your layers in the Layers panel. They should highlight instantly. When you open a panel created as described above, there is a big delay between selecting different layers. You can not resolve this unless you close the extension panel and restart Photoshop.
Is there a solution for this? Obviously a big problem.
I also just tested a panel built on a Mac and loaded on Windows with CS6...no fix, same isssue.
Note, this issue is not happening on Mac with CS6.