Here's what I can say. Running the SoCal springs at 60psig boost and 5250+ rpm didn't float the valves, and I've had no spring related issues since I've been running aftermarket springs (2 years?).
With me, it's kinda like the Crowers. I continue to run them because they do what I need them to do. What you are going to find is that some of these "hipo" parts are breaking, and it's seldom made public knowledge, nor will I discuss what is told to me in private.
But I'm no saint. Back when I was having problems with ATS parts, I kept my mouth shut for a long time, because I wanted some replacement parts. This kind of thing happens a lot. I know that most failures I've heard of DON'T become public knowledge for that reason. Who can blame them? The only reward for being honest in the performance field seems to be poverty sometimes. Poverty is good for the soul, but it's hard to race with it.
Consequently, when I find stuff that doesn't bust, I continue to use it, and I recommend it. And with a Dmax, that's not a real long list. If somebody claims to have these engines figured out 100%, they are lying to sell you stuff. Nobody is making durable HP diesel engines yet. By durable, I mean similiar lifespan to gasoline engines of the same output. It's getting closer every year, but it ain't there yet.
To SoCalDiesel's credit, twice he has warned me NOT to install parts I've bought from him when he found they didn't hold up under big power. He did not make or design either one, he just sold them as part of his product line. I've yet to see any other Dmax HiPo shops ever do that. Heck, in fact, most will even continue to sell parts that they know are having failures simply because it's hard to throw away inventory you spent tens of thousands of dollars on.