i dont think my Yanmar EX3200 has a Power Beyond Plug on the loader valve. This would be the best design for sure. Otherwise i dont know how else to get this done. Basically interrupt the feed line to the loader valve, and pass everything in series prior to it. I agree i would prefer to have the loader be first in line.
Also what i meant for a loop was run my full pressure line to the back of the tractor, and have a quick connect on it. And then have a line going from the back of the tractor back to the AUX valve or loader valve. Then when im not using a 3pt attachment hat has hydraulic needs, just put a loop between the IN/OUT lines on the back of the tractor to pass hydraulic fluid forward. When using a wood splitter, or backhoe, you remove the loop, and tie your equipment to the IN/OUT hydraulic fittings.