Switch (docked mode) – 1080p / 30 frames per second target
Switch (handheld mode) – 720p / 30 frames per second target
As for MGS1:
“arrives virtually unchanged, as this is an emulated version of the 1998 game, lacking widescreen display or up-ressing, which may come as a disappointment for players hoping to play MGS1 on their 4K TVs”.
In my opinion this is a scam.
If you have the MGS HD Collection you can skip this and emulate MGS1 on any device.
You will get the same.