Thanks for pointing me to that thread!
I’ve tried tweaking through all the modes on my Philips to no avail. However, turns out that the Samsung does support 4x mode, as long as you use one of the optimized modes. No tweaking necessary!
On my Philips, PC mode does significantly improve the image. Problem here is that, whenever the game switches resolution, the tv will switch to wide screen when in PC mode. So I have no working solution for these games. Is there any way of making the OSSC output 2x in pillarboxed 16:9 to work around this?
(Speaking of res switching, I’ve gone through the Samsung service menu, changing various settings related to HDMI, but nothing improves or worsens the blackout time…)