I am actually trying some shaders from the repo on PC 0.9.9.6 with Nestopia core 1.46wip.
E.g for sabr v1.1 or v3.0 I receive on a scale value “I dont care” a rotated picture and on every other scale facor a black screen while playing but a screen is showing while in Pause (F1).
Same behavor is on different other shaders,