For the moment, I have found peace with x-h2s color smoothing. If you shoot Prores 422 or HQ in 6.2K standard film simulation, you will get color detail that is at the border to what the sensor is able to deliver. There is smoothing, but less smoothing would soon tend to unpleasant color noise. I saw that also in comparison with my G85 4K, which seemed richer than fujifilm 4K, but having a closer look also revealed "false richness" by delivering color where there is none.
Regarding 4K and if you don't want prores blow your memory card, shoot h265 longGop ~200Mbps, also in standard film simulations, and you get great footage where you will not notice any lack of color detail, unless you really look for it.
And you are right, you will mostly only notice lack of color detail (if any) in nature shots with little color contrast.
f-log2 is less good for such shots. Along with higher dynamic range, the chroma channels are compressed as well, which might be one of the reason that f-log2 has less color detail.
if you want specific modes to compare in advance to your purchase, let me know, I am happy to help.
Apart from color detail discussion, what is definetly great is the 4K 120p (always record at 720Mbps LongGoP, which convert to a 140Mbps Clip, if you want best quality). According to dpreview Video Stills Comparison Tool, its even better than A7SIII in terms of details captured. I saw only GH6 might beating it a little here.
The magenta cast in the reds I also noticed and don't like so much, but I understood fujifilm did that on purpose to please skin colors (see interview link below). You can easily correct in post if you want (hue vs hue curve in resolve for example). Also some of their film simulations don't have it as strong (I think also eterna tends more to red compared to provia)
For skin color captures I believe there is nothing to complain. Here the smoothing tends to even give advantages. My G85 skins are clearly worse, especially at higher ISOs, where X-H2s keeps colors under control pretty well.
Unfortunately I don't have its real competitors in my hand so I am limited in comparing them.
The link to the interview:
https://www.fujirumors.com/fujifilm-managers-talk-film-simulations-origins-evolutions-goals-misunderstandings-bold-classic-negative-and-much-more/