RGBSource

Two blockers for 4K output: 1. No manufacturers make generic 18Gbps TX ICs - current 18Gbps transmitters are integrated as part of ASICs 2. Cost of FPGAs that can transmit data fast enough are still $200+ parts That said there are a number of 4K TVs that can cleanly 2x scale 1080p to 2160p. Some 2017 models include the Sony X900E, and LG's OLEDs.

The original Analogue Nt shipped with either the NESRGB (standard) or the Hi-Def NES (upgrade) installed. The Hi-Def NES Nt option provides composite output from the PPU via DE-15 connector pin 12. This only applies to the second/final production run (polycarbonate base plate). I've never actually tested composite video out on my second batch Nt, but would imagine composite output would also require the HDMI cable to be disconnected from the NT/HDN per standard design (or else the picture will look really weird). https://support.analogue.co/hc/en-us/articles/216203167-Analogue-Nt-FAQ

The v2 Zeldaxpro version of the GCVideo didn't live for very long (a bump killed the console and PnP): https://twitter.com/MetalJesusRocks/status/900363675415879682 Going to install the KNJN PlutoII with the collingall bracket!

The UltraHDMI with the latest FW (v1.05) can produce a nice 1080p scanlined image (Integer+ with Hybrid scanlines). The on screen area of a pixel appears in part to be a function of its intensity, rather than a fixed/simple scanline "overlay". It would be nice if other devices could do this!