[-Vit-]

There's not much point comparing QTGMC with TGMC - it's the same algorithm, the same script at it's core.
I deliberately designed the defaults on QTGMC to be about the same as TGMC. So just use QTGMC()

There are QTGMC settings that will give you even more exactly the same result as TGMC, something like this (for NNEDI3):
QTGMC( preset="Slower", border=true, svthin=1.0, lsad=1600, precise=true )

But yes, Placebo smooths too much on clean video. There was some discussion of it many pages back. I won't keep that setting in that form. Try setting TR2=1.
Or use Slower or Very Slow. And use Source Match, that's genuinely new, genuinely accurate, and nicely slow for people who like placebo settings.

The most "accurate" reasonable settings I've measured (measured by best SSIM that doesn't introduce any noticeable artifacts) are:
QTGMC( Preset="Very Slow", EZKeepGrain=0.5, SourceMatch=2, Lossless=2, Sharpness=0.1, Sbb=0 )
Although the exact EZKeepGrain and Sharpness setting depend on noise and motion in the video respectively.
Can get a little more precise with multiple calls to QTGMC or specialized pre-filters, but really it's not worth it.