Requirements:
Brightness of at least
1000400(?) nits<15~12-16''
Preferably high viewing angles
Insights:
True, industrial-grade high brightness outdoor monitors might be prohibitively expensive. We might need to settle for relatively high brightness portable monitor intended for productivity or gaming use cases, while ensuring proper visibility with solutions like anti-glare coating.
Options:
Lower brightness:
Higher brightness:
...
HDMI Splitters
https://www.amazon.com/Splitter-Aluminum-Switcher-Bi-Directional-Support/dp/B09D7MRPJF