[-Vit-]

I looked at sadie's example - I don't see a topmost black line - I see a darker line on the second line. And, yes it dances on QTGMC defaults - and the difference from TGMC is that you need Border=true.

The QTGMC docs say of Border: "set true you see flickering on the very top or bottom line of the output" (yep I guess that needs to read 'lines')
There's section at the end of the docs comparing with TGMC which also answers this question.

You set edimode="nnedi3" on TGMC, only modded versions of beta2 support nnedi3, in the original version that will just do a bob. So let's be exact:

TempGaussMC_beta2() is the same as:
TempGaussMC_beta2( 2,2,1, 4,0,4, "eedi2" ) is the same as:
QTGMC( preset="Slower", edimode="eedi2", border=true, svthin=1.0, lsad=1600, precise=true )
[Corrected - thanks Taurus]

The other default differences: Precise switches on/off barely visible steps for a small speed-up. lsad is different because the MVTools documentation is especially confusing on whether that setting should be scaled by blocksize - I had to read the MVTools source code to find that it shouldn't be.