I finally hooked up my PAL Amiga to an LCD monitor with the OSSC. HiRes (640×256) mode looked perfect. HiRes Laced (640×512) flickered the same way it would on a CRT. Which is good because it meets the old standard (there’s no regression), but I hope 480i/576i lineX2 would eliminate that flicker.
Also, the Sega Genesis/Mega Drive flickers slightly on Sonic 2 in 2-player mode. It’s much less noticeable than the Amiga laced modes, maybe because of less contrast in the game compared to Amiga Workbench which consists of lines and fine text, but in any case it would be interesting to see how close to flicker-free the OSSC could get with 480i/576i sources.