I agree that if you are going to modify the hard line in any way you might as well reroute it to put the loader valve first, and in series with the 3pt valve, rather than in parallel with the 3pt valve and having the 3pt itself ‘blocked off’ through the descent speed adjustment. That is a ‘kludge’ that someone would only do if they WERENT willing to modify the existing plumbing. But now you are!
Need to see a pic of your loader valve though to make sure it is safe for ‘power beyond’ usage.
Also, the connection from
your hard line to your pump outlet looks like something someone makes a spacer block with external ports for. I thought i saw it for a Yanmar but i could be wrong or could be the exact same thing fits both. But someone makes a spacer block that fits between a round pump flang and round hardline flange with 3 bolts that reroutes fluid through your external attachment before continuing on to the 3pt. Hopefully someone reading this will recognize the reference and be able to direct you to this part/company because all ive got is the knowledge that it exists.. somewhere..