Hi,
I'm not sure what settings you are referring too.
The TV doesn't have to downgrade as such, i can just choose the display mode 4:3 or Widescreen, 16:9, zoom etc...just like you would on any LCD TV i guess.
There are dip switches and a trimming capacitor for adjusting the settings. Assuming that your adapter has a case, you need to undo the screws and open the case to get access to the dip switches and the trimming cap. Info on how to adjust them can be found in the link below.
http://www.amigamaniac.com/V3_RGB_adapter_notes.htmlHope this helps.
