Okay, I think I found out an option that might help you, although it requires a full re-encode to ProRes. ProRes is what I use to capture my footage, and it is nearly a perfect representation of the original pixel data. It is compressed, but it's such a small level of compression that it's not going to impact your final encode in any visible way. ProRes is often used during post production of products because you can potentially re-encode it multiple times and not notice a difference. The main drawbacks then are the time it takes to create this intermediate file, and that the file will be huge. Here is the command line I used:
ffmpeg -i input.mp4 -c:v prores_ks -profile:v 2 -vf "setparams=color_primaries=bt709:color_trc=bt709:colorspace=bt709" -c:a copy output.mov
I've used the ProRes 422 format here. If you don't mind using extra file space, you can use the 422 HQ format which is even less compression by changing to -profile:v 3, although personally I don't think it's necessary unless you're doing several re-encodes. There are also profiles 4 and 5 for even less compression if you're crazy lol
Then you should be able to import that into Premiere, and Premiere will think it's looking at a rec709 file, meaning you can perfectly retain color information while exporting with Voukoder, and not need to use my preset as a workaround.
Here is the mediainfo of the file I created:
Here is the video imported into Premiere:
And here's what the original video looked like imported into premiere. before using this method to strip the HDR metadata:
Here's a tonemapped version using MadVR's default tonemapping: