I am glad I found this thread. Has anyone gotten this to work properly? Currently I am experiencing what Mark originally posted, only in reverse. Right now in a Quebec instance, when opening a chat from the ESC, I am still seeing the default experience. I configured a new record called "HR ESC Experience" where the condition is 'portal=esc' and order is 90. In the default experience I have no promoted topics, and in the HR ESC Experience I have 3 promoted topics.

Strangely enough, a day ago, I marked the HR ESC Experience Inactive, saved and then marked Active again, saved and it worked as expected. Today, I opened the exact same instance, and the experience reverted back to the Default experience. 

Thoughts??