Custom results reporting with test step pass/fail

I have seen all these, but still it seems very bad that SmartBear does not have some documentation to explain what the shape of the .json data can be and is parse as.  For eample, https://github.com/SmartBear/zephyr-scale-junit-custom-format-example/blob/main/zephyrscale_result.json.  In that json file it has some details in executions but what keys are supported?  What ones are not in that example that someone can leverage?