Rebuild or recycle?

The last three months my truck has been needing work left and right. It all began when my radiator cracked and drained everywhere. So I figured that I should remove the ERG as it was more than likely damaged. Completed that then wouldn’t start, next fix was HPOP was dead and needed a new one. After that Stuck VGT Veins and a lack of power. Sorted that and then here is where thing got interesting.

Afterwards I took the truck for a short drive about 1000 miles. I noticed once I started the trip, I could hear an audible hissing sound when the truck when I was driving and when the boost exceeded 20psi and it would go all the way up to 28psi and then make a choo choo sound like negative pressure had built up and the turbo was blowing it off or pushing it backwards. Also I had a loss of power even though I was pressing on the accelerator and the boost was climbing. The hissing noise slowly started becoming noticeable at lower and lower boost pressure (like 10psi) until the boost would climb and the turbo would make the stutter sound. All while I would lose speed when going up a hill. I stopped and shut the truck off, because my tuner (not installed) was showing oil temperature of 240 degreed but the coolant was down at 198. These temperatures are way outside of what the Ford delta-t recommends and it was not normal to what I’m used to seeing.

I opened the hood and saw gray foam seeping from the coolant reservoir. I didn’t restart the truck and had it towed to a dealership where it sat for 3 weeks, and they didn’t turn a wrench on it.

I was not pulling a load it was just me and some gear in the back no more than 500lbs additional weight.

Recent fixes are:
EGR Delete
Upgraded Oil Cooler
Radiator
HPOP
VGT cleaning

Help I like my 2005 6.0L Diesel Excursion. We get complements everywhere we go. 409387 miles. I'm just hopping that I don't need a total rebuild. Thank you.