The F2T oil cooler is not an issue, or it would be a bigger problem on bigger turbos making more power = more heat, but it isn't.I think the killer of the vj11 for the Mx6/Probe is no real oil cooler, and the crappy stock blow off valve
The crappy factory bypass valve could very well kill VJ-11 turbos trying to run 15psi, because it leaks above 12psi causing to turbo to have to generate more compressor boost to deliver 15psi.
I have always done the chip, bov and boost control together. So I can't contribute any of the many dozens of IHI turbos my shop partner and I has disintegrated over the year. I can tell you my ported and polished heads are VJ-11 killers.