ToneMap settings greyed out, encoding with ToneMap enabled fails

[Selur]

ffmpeg aborts with:

Unable to find a suitable output format for 'zscale=tin=smpte2084:min=bt2020nc:pin=bt2020:rin=tv:t=smpte2084:m=bt2020nc:p=bt2020:r=tv,zscale=t=linear:npl=100,format=gbrpf32le,zscale=p=bt709,tonemap=tonemap=clip:desat=2.000:peak=0.000,zscale=t=bt709:m=bt709:r=tv'

which indeed does look wrong.
will look at it after work and report back