wdsi cookie Is Causing Cache Misses

Team WPMU,

I've been seeing some performance issues on my network and after troubleshooting, the wdsi cookie (wdsi-on_hide) is causing problems with caching and preventing pages from loading properly.

I'm in the process of swapping out slide-in with Hustle, but want to make sure Hustle doesn't use the same cookie.

And, if Hustle does use the same cookie -- well, there is a problem with how that cookie is implemented.