this post by maukka has measurements for the 5000k 219c as well as the 4500k 219b.
fwiw, your garden photos do not contain much Red, which could be used to show the effect of R9 CRI (except the beak of the bird):
also, I respect that you are seeking to show that the 219c is closest to sunlight… it is, because the Tint of sunlight is above the incandescent BBL:
here you can see the jog in the BBL, at 5000k it steps up to DUV 0.0032 (in the pic above that is show as the D50 reference)… you can see the 219c is very similar in CCT and DUV, to the D50 reference.
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(ignore the arrow and duv value from another post)
here you can also see the jog in the BBL:
I agree the sst-20 4000k has the most yellow Tint, it is also Warmer CCT… which brings me to my next point, about comparing LEDs to daylight. That is fine, for LEDs above 5000k, used during the day, when the brain is white balanced to sunlight.
otoh, at night, when the brain is adapted to incandescent, 5000k, even 4500k, looks more cool Blue than necessary…
imo, for LEDs used during the day, it makes sense to compare to daylight… otoh, for LEDs used at night, I do not choose CCT above 4000k… I prefer 3000k or 3500k…
point being, when my brain is adapted to nightime lighting, it is using a different CCT (3000k), and a different DUV reference (0.0000), than sunlight (5000k and duv 0.0032)… at night my brain is using Incandescent as a reference (not sunlight), because thats what my house lights are…