One of the benefits of 32 bits effects are their ability to retain all details in the image, even if you overexpose it early in the chain. Try for instance to over expose a clip using ProcAmp, and then add another ProcAmp on an adjustment layer, and lower it. The details are back. This is because ProcAmp is marked as a 32 bit effect in the Effects-tab.
Lumetri Color is also marked as a 32 bits effect. Still, if I lift up the Lumetri Exposure so parts of the image is clipped, the Lumetri Curves will not bring back the details. This also applies if I crank up exposure in one Lumetri Color and then reduce it in another Lumetri Color (or using another 32 bit effect, like ProcAmp), either on the same clip, or on an adjustment layer. The details are permanently gone. Even if you overexpose with the Exposure slider and then lower it again with RGB Curves in the very same Lumetri effect. This tells me that Lumetri is NOT 32 bit but 8 bit. Or am I missing something here?
I have also tried this with LUTs. LUTs are applied first in the chain. It will definitely cause some parts in some footage to clip, and that clipping is not possible to fix later in the very same Lumetri Color. It helps if I apply a second Lumetri to all clips and apply the LUT there instead. This can't be the correct work flow, can it?
I have tried only with Windows 10, on two computers, both with GPU acceleration (Cuda) turned on. It doesn't help to turn on max bit depth in the sequence settings, or using high quality playback in the Program Monitor.