Tested in game mode with SHVC-CPU-01 board SNES via SCART using an assortment of games and 240p Test Suite
2x works perfect
3x works, slightly window boxed and colors a little washed out. Also switches TV out of game mode
4x stretched picture, window boxed, washed out color, switches TV out of game mode
5x works, switches TV out of game mode, muffled audio, slight overscan, cuts 3 pixels off the top, 5 off the bottom, and 1 off the left
Manual input lag test shows about 1 frame input lag
This is using HDMI 1 input, HDMI 2 yields slightly better results with better game mode support, but not enough for me to switch and have the terrible results my PC has on HDMI 1.
After doing some tweaking to the OSSC’s advanced sampling options and the TV settings I’ve got all modes working nice. The washed out color and muffled audio was because of the TV changing modes, changing the settings in that mode got the picture and sound back to normal. 3x is still slightly window boxed and 4x/5x are still slightly stretched, but not enough to really matter. I’ve been playing in 5x and it looks/plays incredible.
After some more tweaking advanced sampling options on the OSSC I’ve got 4x to display in the correct aspect ratio.