I tried cascading the non-powered WB68s during my whole house install about 10 months ago and had no luck. I got three WB 616s which are a powered MS and have had no problems. BTW, I had a pro installer team do the install and paid a lot but I'm glad I did. I ran between 4 and 6 lines to each location so that I could try and future proof the installation.
Hope this helps,
BigBearf
