In Resolve you can start to decode to P3-D60 and Linear in the RAW tab then do a "Color Space Transform" from the effects tab. Transform to your timeline space, like REC709 Gamma 2.4 then check the box "use custom max input" under "Tone Mapping" and set it above your screen brightness like 250, 500, 1000. You should see your highlights snap back and roll off nicely if they were available. I wouldn't underexpose to try and get them if you are at ISO 800 because the shadows can block up.
I usually do Noise Reduction in the first node, then CST in the 2nd node, then color and contrast correction in the 3rd with the lift gamma gain tools.
I attached two screen shots of the decode and CST.