A few updates since, Vdash team sent me an update once, but it didn't change anything.
I have tried it with a full chip dice, blis enabled, disabled no difference,
I have tried it with the original mirror no difference
I have tried it with a LOT newer DDM blis enabled and disabled (from a 2013 xc90), it did the exact same thing
I have tried it after reverting the PDM to the original settings no difference
I am out of ideas and I have spent hundreds on it so far...
PDM update went through no issues straight away, BOTH DDMs are installing the update and then 20% into the detection they go bootlooping.
PDMs are alive but bootlooping, confirmed by vida.