Here are some workarounds I would suggest, maybe using a combination of a few different options could give you the results you need.
Option:1
Chop the sample from "X" measures to equal 1 measure parts.
"chop 1(of 4)" to the first step on the sequencer on the First measure
"chop 2 (of 4)" to the first step on the sequencer on the Second measure
"chop 3(of 4)" to the first step on the sequencer on the Third measure
"chop 4(of 4)" to the first step on the sequencer on the Fourth measure
Option:2
Use the "INST EDIT" on the sample loaded.
Press [EDIT] and the [PAD #] the sample is located on to access "INST EDIT".
Make adjustment to the sample as needed.
Main focus would be adjusting the Decay Offset as well as Release Offset. I would suggest starting from "-64" and working your way up if needed.
Possibly using a combination of both options 1 & 2 will be needed.
Option:3
Place the Long Sample in a "VOCAL TAKE"
When selected on [SONG], load the sample to a "TAKE" by pressing the Pad # and [ENTER] on the Value encoder.
Apply the TAKE to the measure desired.
