Dang, that's a lot to drop considering all you've already done. I'd call around for a second opinion. I had a shop give me a similar diagnostic on a vehicle once, then I took it to the "specialty" shop for that make, and the guy said. something along the lines of "well...they all do that, so it's not that big of a deal, keep an eye on this, that, etc."
Is there a 7.3 Powerstroke place near you? Or some other diesel specialty shop? The 7.3 is well-known at some shops, and never seen by others.
Not sure where you are in WA. NW Powerstroke in Vancouver, WA is a good shop. Quick google search shows me some specialty shops like NW Diesel near Everett, Total Performance in Tacoma, or something similar near you.
Is there harm in parking it for the time being. Sucks to be out the fun project vehicle, but maybe realize where you are/aren't in the whole build process/timing/$$/etc. and make a call from there. I'm not in the service, but I can't imagine a lot of free time in OTS...? Maybe wait until you've got the time to dig in and do it all yourself? There are 8 injectors and glow plugs, so it may be worth taking the two (or more) out & rebuilding/replacing as necessary.