Perhaps you can pre-process your data before feeding it in Mathematica? If so, I'd suggest you consider Data Transformer (disclaimer - I'm its developer).
It offers a number of conversion settings (with sensible defaults) so you can match the data for your purposes. You can choose how to treat XM attributes, embedded text etc.
It's available on the Mac App Store and the Microsoft Store.
Here's Data Transformer's JSON output with the default settings for your example:
{
"root": {
"fair": {
"there": {
"fog": "balloon",
"flew": "load",
"slipped": "pan",
"shine": 1616809877.197722,
"general": "warm",
"stock": "pale"
},
"higher": 273906901,
"environment": 673083878,
"raw": -1195497107,
"lunch": 1930133836,
"body": "wool"
},
"green": 831388325,
"writer": -465508588.16013575,
"chest": "touch",
"score": -969560157,
"aboard": -1575070350
}
}