Yes, we tested it, and I missed that deinterlace is broken - just noticed it now We're already working on it.
To verify output mode you could check if your TV/display has some kind of diagnostics / info menu. My LG C8 is unfortunately a bit too old and only tells me resolution and refresh rate - newer models should also report color format and bit depth.
popcornmix checked with his HDMI analyzer and we both checked dmesg - with drm.debug=0x02 you'll see the mode and bit depth buried in tons of other logs, eg
[ 73.507849] vc4-drm gpu: [drm:vc4_hdmi_encoder_atomic_check] Mode 3840x2160 @ 60Hz: Found configuration: bpc: 12, fmt: YUV 4:2:2, clock: 593407000
or
[ 152.031004] vc4-drm gpu: [drm:vc4_hdmi_encoder_atomic_check] Mode 3840x2160 @ 24Hz: Found configuration: bpc: 12, fmt: RGB, clock: 445054500
so long,
Hias