I understand that if you have a PWC ZW and it is powered up after your Legacy Base, the Legacy Base takes control over the PWC ZW. I have this scenario, and I always power up my Legacy last, so I always have ZW control, along with my TPC 300/400 blocks. I have found a new discovery(maybe not, but for me it happened): I have separate powered loops with TPC 300's, on a separate power strip, when these are powered up(turned on with the toggle switch) after a Legacy power up, the Legacy unit has some sort of default control over those loops. I don't know if it is because of the 1.51 version, but before this never happened.
I have 5 loops, usually run 3 together with my power strip, TPC 300/400. I also have 2 other loops on a separate power strip. I don't always turn on those 2 loops, but now when I do, after everything else is running, Legacy seems to go into a default control on them. This hasn't happened before, so I believe with the 1.51 version, this now happens. The conclusion would be that to power up everything first, then power up Legacy.