What about adding to Aseprite a kind of retro CRT shaders while editing? (or at last for preview)
See here for example (Web GL demo):
For a closer look, see this image (comparison of the Famicom version of Wizardry (1987), on a CRT screen vs current HD monitor):
And imagine you draw with that old CRT preview directly in Aseprite (including “zooming in the shader” like in the image above).
All the best,
PS: full article including this image: