And if I don't, feel free to call me an idiot. You won't be the first or last.
In a "normal" open center type configuration, you have oil coming from the pump and into a spool valve of some sort. When the valve is in the neutral position, a gallery is open between the pump in and tank out and fluid just flows through the valve unimpeded. If the spool is activated, flow is directed to the device controlled by that spool and blocked from the return passage.
Q1 - is this correct?
A power beyond kit seems to create additional pump in and tank out ports on the valve. With nothing connected beyond the valve, these ports would be capped shut and the valve operates as described above.
Q2 - Is this correct?
If you install another valve "beyond" the aforementioned valve with PB, you plumb that valves pump in and tank out ports to the primary valve and the pass through gallery is blocked in the valve with the PB kit installed so that pass through now flows to the beyond valve and back.
Q3 - is this correct?
So if I wanted to add another function elsewhere (say a rear SCV to control the angle cylinders of a back blade) what would be the difference between simply "splicing" into the existing tank return line or installing a PB kit? I understand that the existing SCV would have priority in either case. I guess what I'm wondering is what does a PB kit bring to the table besides potentially easier plumbing?