There is currently a limit of -100ms up to 100ms. Would be nice, when this would be hihger for samples like this:
Bitwig goes from -500ms up to 500ms. I think this would be enough or maybe even higher. In FL you can get even -5000ms.
Another solution would be per sample delay. This was suggested here several times:
I currently created a tool for adding the right amount of pre silence, so i can better time swosh or reverse cymbal samples. I think autoseek could be used here for negative delaying a sound, would be extremly powerful. VSTi VPS Avenger do this for the interal drum sequencer.