No, Sony Megatron Color Video Monitor aims to simulate the appearance and functionality of the CRT’s RGB Phosphors and Mask by aligning the RGB subpixels of a modern-day display with the simulated subpixel mask then using a brute force method of shining as much light from the display as possible through these simulated phosphors and mask in a manner that’s as close as possible to how a CRT would have functioned. There are no additional subpixels being activated or at least in theory there shouldn’t have been in order to achieve this end.
To make the Mask translucent and have the base colour mixed in with the phosphor colours is not the way things would be done on a CRT and if done so in Sony Megatron Color Video Monitor would take things in a direction of looking less like a CRT.
The close-up photos of Sony Megatron Color Video Monitor in the first post are evidence of the soundness of this concept.
I’m not sure if I asked this before but why not use CRT-Guest-Advanced or other shaders if you’re not after an as accurate as possible simulation of the RGB phosphors and mask down to the phosphor level (which by the way, CRT-Guest-Advanced can also do)?
You can even use HDR with almost any other shader through RetroArch’s built-in HDR Support or through other means like Windows 11’s AutoHDR or Lilium’s Tonemapping plus Sony Megatron Color Video Monitor’s AutoHDR for ReShade.