I was going to use overpass-turbo to find other nodes that have lamp_mount=lamppost.

I would like to use "What iD shows are commonly used values. Many of those values can be wrong,"

This might help explain why the list of tags in a wiki is so much shorter than those that seem available in iD.

Going forward I'm not touching anything that might affect a router unless it involves adding something.

While I believe OSM would be generally helpful, most have never heard of it, but its still used in popular products like CityMapper.

That said, anything I tag, I'll run though one of the external tools you mention.