Ok!
I took 7 different shots of the same scene and downsampled 2 of them, so all in all 9 shots to compare. I uploaded them to Abload, so you can compare them using browser tabs. The shots are taken from Dragon Age:Inquistion with reshade using the freecam, but no other tweaks (besides hud hide). Reshade does color toning here and SMAA, as well as in some shots Lumasharpen (0.6, using defaults for the rest).
I hope I have pasted all URLs with the proper descriptions!
1920x1200, Res scaling 1, LumaSharpen:
https://abload.de/img/1920x1200_1_lst7qg7.png
1920x1200, Res scaling 2, LumaSharpen:
https://abload.de/img/1920x1200_2_lsqsop3.png
2880x1800, Res scaling 2, LumaSharpen:
https://abload.de/img/2880x1800_2_ls6ns8s.jpg
2880x1800, Res scaling 2:
https://abload.de/img/2880x1800_2_nlsc9sje.jpg
2880x1800, Res scaling 1.5:
https://abload.de/img/2880x1800_1.5_nlsoju0f.jpg
3840x2400, Res scaling 1, LumaSharpen, downsampled to 2880x1800 (lc3):
https://abload.de/img/3840x2400_1_ls_ds_288rgpmr.jpg
3840x2400, Res scaling 1, downsampled to 2880x1800 (lc3):
https://abload.de/img/3840x2400_1_nls_dsuho6x.jpg
3840x2400, Res scaling 1, LumaSharpen:
https://abload.de/img/3840x2400_1_ls2kst2.jpg
3840x2400, Res scaling 1:
https://abload.de/img/3840x2400_1_nlswkqro.jpg
If there's any texture interference it's in the chainmail arms/shoulders in the armor and the grass on the left. I must say I don't really see any issues with resolution scaling at 2, things are sharp and look pretty fine. Downtuned resolution scaling a bit does give some more detail but less interference (if you see it at all, I don't). Lumasharpen might overly express some sharp edges so for screenshots with resolution scaling and at a higher resolution through hotsampling it's rather overkill, but for some scenes it might still add a little extra detail.
So there you go
