@breezyjr, sorry i didn't quite follow what you wrote.
The issue with the ESC/BEC is that your BEC is powering your RX, but you also have the ESC throttle cable plugged into the RX. If the negative wire on the throttle cable, is 0V but the BEC negative is at 25V, you're going to have a short from the BEC negative to the ESC negative. That is why they need to be the same.
The only way it would work is if you opto-isolated the throttle signal.
I changed my wiring this afternoon... Originally, I had the CC BEC pro connected to the positive side of my series connector.... after making my own series connector, I connected it to the negative side of the series connector... Hope that made sense....
Running a helijive 120, with the red wire removed. Both leads of CC BEC Pro connected to Skookum 720.
On the bench, everything seems normal.... But I think I know what you mean about connecting to the pos side of a series connector... cause when I plugged everything in, with the original wiring, got what can only be described as a short when I plugged in the pos side of the series adapter.... which is why I redid everything... now it seems to work just fine.... Just freaked me out a bit with the short... you know with Lipo fires and such, I started ripping the wires out when I shorted... (well think it was a short... certainly made a weird noise, and the plug almost melted (deans) together.... YIKES! 1st time that's happened to me.. although, I usually use WR super BEC, which, as I understand, can handle the 12s setup... Had the BEC Pro laying around, and didn't have a WR super BEC.... We'll see how it works tomorrow, but I'm sure it'll be fine. Was able to program the helijive after the rewire...
Later,
Joe_Breezy