"I can't remember exactly how 4:x:x works, but that is de-interlacing technology, not upconverting resolution."

It has nothing to do with deinterlacing.

4:2:2 means for every 4 luminence samples, there are 2 R-Y and 2 B-Y samples.
4:2:2 has half the chroma resolution of 4:4:4
4:2:0 has only one sample of chroma for every 4 liminence samples.

MPEG2 is encoded using 4:2:0 video, you have no control over this.
'Upsampling' a 4:2:0 image to 4:4:4 does not result in an increase in quality whatsoever.