Then don't expect it to look exactly the same. But try these settings (not my own findings), and compare the originals in your viewer to the rendered ones. You may need to ignore the proxies:
"Current settings to get the best visual match between Resolve viewer, Iina, QT player and iPhone on an M2 max XDR display and the Flanders CM250
Mac display profile(s):
1. HDR Video (P3-ST 2084) (got that from here, currently using this profile)
or
2. HDTV Video (BT.709-BT.1886) (Apply System Gamma Boost turned OFF)
Resolve settings:
Preferences -> System -> General
1. Use 10-bit precision in viewers if available CHECKED
2. Use Mac display color profile vor viewers CHECKED
Resolve Project settings:
Color management
1. Timeline color space: Rec.709-A
2. Output color space: Same as Timeline
Resolve Export setting for ProRes:
Advanced settings
Gamma Tag: Same as Project
For my own reference, but thought it would be good to have it here for others to discover
Strangely the default HDTV Video (BT.709-BT.1886) display profile seems 100% useless because of the gamma boost setting.
Steve added:
What I've found is that I must set my output color space and gamma to match my monitor and my delivery (my intent is to grade in 2.2 and deliver an output via CST to Rec709 gamma 2.2. With the viewers set in Resolve to use the Apple display profile (and the profile set to BT.1886 customized to gamma 2.2 I get an image in Resolve that looks identical to the feed to my external monitor which is also calibrated to gamma 2.2. So I'm good with this setup. Setting the custom BT.1886 to gamma 2.2 seemed to do the job. I tried setting the boost to 1.09 but didn't see any difference in the output but that may be because I'm using a gamma of 2.2 in my output from Resolve (output color space / gamma 2.2).
The only time I set tags to Rec709/Rec709-A is in the output file (does not encode as Rec709-A, this is just a trick tagging as explained in the post process article I linked to earlier.
So now I get agreement between my MacBook XDR display in Resolve, my external monitor and when I output my test video to YouTube and view it on my iPad Pro, it looks close enough be satisfy my needs.
Testing a bit more with the boost of 1.09 I found that the output file tagged 1-1-1 actually has a better correlation in the darkest regions with the Resolve viewer and my external viewer (so as viewed in QuickTime) so this is good to know.
Andrew added:
For those reference BT.1886 modes file has to be encoded with 1.96 gamma (Resolve Rec.709+2.2 gamma presets doesn't export 1.96, so this is a special case). Rec.709 Scene or 2.4 will export 1.96 encoded file, so then depending on your boost in ref mode setting you can have 2.4 or 2.2 final viewing. Thos are not pure gammas, so this may be a reason why it matches your ref screen better than pure 2.2 export+ 2.2 preview curve.
If 1.96 encoded file does give same preview as ref screen through ref mode with correct boost then this is actually good news
Apple ref modes work very different than I thought, but at least now it's known what to expect.