Questions about AVerMedia Live Gamer Ultra

No, according to the product data from the manufacturer, this device can only reproduce 240Hz at 1920 x 1080 pixel.

According to the manufacturer, the "GC553" is also compatible with the X series. You can find more information on the following link: https://www.avermedia.com/event/console_gaming/

It's HDMI, as long as the resolution doesn't go above 4k, any signal transmitted via HDMI works (It's HDMI, as long as the resolution doesn't go above 4k, any signal transmitted via HDMI works)