16 bit float export looks weird in other applications, but 32 bit float is fine

Did not come out OK with my (quite old) version of Photoshop. Imported very flat as if it assumed a gamma of one. Converting to 16bit mode with a gamma of 2.2 restored the contrast but still left the colours washed out. Have you tried saving it with an output profile that specifically has a gamma of 1.0

As I mentioned in "Clip out-of-gamut colors" check box - #76 by RichardRegal the only way I could get a picture to look the same in both programs was to use an output profile with a gamma of 1.0.

I did submit a bug report as Floating Point Exports have the wrong gamma · Issue #5893 · Beep6581/RawTherapee · GitHub but the consensus there was a problem with how other programs interpreted things then it was not a problem with RT.