Darktable/Gimp how to fix daylight photos shot with Flash white balance

It’s darn hot outside so I’m editing photos…
Here’s my effort at 4600K. The pic says taken at 08:42.
I think my whites are whiter than some of the above (at least on my screen).
@pittendrigh , I was wondering what the round patch is on one of the bird’s underside, say X=3/5, Y=1/4, starting from bottom left.
DSC_8957-Avocets-rawconvert-edit-V1-SN-sRGB.xmp (49.3 KB)