My understanding is that Canon Log 3 is still preferable for flexibility in post-processing though HDPRQ requires simpler post-processing work to get good results.. My research indicates that both are are 10-bit color depth. You only have the option to HDRPQ on the R50 so that comparison appears to be moot for the R50, but the R50V will Canon Log 3 once you get your R50V.
Disclaimer here is that I have neither of these R50V devices and have only every processed Canon Log 3 with Davinci, and not HDPRQ so I'm just interpreting what I'm reading and hope that I got it right. If not, hopefully someone with more first-hand HDPRQ experience will jump in and correct me.
Thanks for being a part of the forum and giving the R50 and R50V a chance.
For HDRPQ my understanding is that you don't use Canon Log LUTs because PQ uses the ITU-R BT. 2100/ST. 2084 standard, not log curves. Thus, you would just use color space transform adjustments in editing software (like DaVinci Resolve) to map to a working space (like DaVinci Wide Gamut). Then you can convert to SDR, or keep it in HDR for HDR displays.
Using HDRPQ it appears that your workflow would be a bit different than you are used to as LUTs aren't really a part of the HDPRQ workflow.
Once your get the R50V you can choose Canon Log 3 and revert back to your workflow of applying LUTs if that is your preference.
I can say that I have used Davinci with use color space transform adjustments in DaVinci Resolve on Canon Log 3 video with what I would consider satisfactory results. It was a hand-tuned job, but as I hardly ever shoot video it was fine for me (and my son, whose wedding I was recording), but it wasn't a production workflow.
