Not sure if this is on the right track or not, I am also not in the secret finding discords so maybe they already know where this crate is and I am totally wrong, or they all figured out as much as I did within the first 30 seconds…
In the total off chance this information helps someone further locate the chest I figured I’d add my ‘best guess’. If there is already a posting regarding this please let me know I can post there instead - I could not find anything via the search function.
Sandy Ransom Note -
“From flats to bends
At Rustmaul’s end
You’ll find the truth
To this crate’s end”
I believe this crate might be located somewhere in south eastern Thousand Needles, in the flooded reservoir area.
The area used to be called “the shimmering flats”, inside that area there was a sub-zone called ‘Rustmaul’s Digsite’. Those two facts seem to satisfy the first two parts of the clue - however I do not see how it relates to the second half.
I have also scouted the area - now known as the ‘sunken dig site’ and was not able to find anything myself (however it’s entirely possible I missed something).
I feel as though this information is likely already outdated or disproven so please take everything with a grain of salt.