The json data would be the code block for weather station. Each of those numbers represent a tile in the code block you pointed out.
In order for the function to be able to display tilemaps of higher intergers than 256 we had to adjust the function.
In the code block for weather station we had to change the math. For example to print out a map at 300 tiles we go 1, which equals 256, then subtract the total number by 256 and there is your second number. Repeat for Y.
I think we changed to uint16 from 8 for a reason but i can change it back and see what happens. I would really like to add a ton more content but its getting slim.
I tried adding to progmem over flash but there was no change