I have a sample with 3000 sample lenght. Inside it, I have 3 samples, they start at 0, 1000 and 2000 respectively. Of course, each sample duration is 1000 (1000 + 1000 + 1000 = 3000).
I added this sample wav file (which itself already contains all 3 samples) to Polyphone, then I added it to an instrument 3 times. Then on the first "sample" inside the instrument I configured "Sample start offset" as "0" and "Sample end offset" as "-2000" (it only accepts negative numbers so I assume it counts from the end). So when I play the note of this sample it starts playing correctly at "0" but it plays the entire wav file, it does not stop at "-2000".