Higher resolution files grabbed by Sonarr/Radarr often end up being HDR and if I'm trying to keep my library SDR.

Is there a way to use the filter command in the [HDR] section to accomplish this? I tried combining a few filters together with commas and semi-colons but it always gets to the FFMPEG command then fails with "Error opening output files: Filter not found". If the whole log file would be helpful I can post it, but I'm also definitely not an expert so it's possible I'm messing up the filter.

Here's an example of what I tried:
filter = zscale=t=linear:npl=100;zscale=p=bt709;tonemap=reinhard

If this isn't very reasonable and HDR to SDR conversions aren't one-size fits all that can be managed like this then I'll just find another system to manage it. Thanks for your time!