I bought a $35 backup camera/display to solve that problem, then discovered that the display contained an AMT630A video processor with a surprisingly capable OSD system. That sent me down a rabbit hole of I2C probing, firmware dumping, register tracing, custom graphics, bitmap formats, hidden factory menus, and eventually figuring out how to use an ESP32 to generate a programmable HUD over the live composite video.
I ended up turning what I learned into an Arduino library, which I've released on GitHub. It supports built-in and custom fonts, multiple OSD windows, 16-color bitmaps, palettes, transparency, and animation. It can also be used with composite video sources other than the camera.
The library and code are here: https://github.com/mogrinz/AMT630A You can also install directly from the Arduino IDE Library Manager (search for AMT630A)
Would "rear view mirrors" help navigation in the suit? So 2 extra displays that would give you a view of what's over your shoulder, like on some cars nowadays (for example): https://www.carscoops.com/2022/02/heres-what-you-wanted-to-k...
(sorry if they in the video - I generally don't watch the videos before reading the text first)