Sustain Looping back and forth with crossfades and modulation like Ableton's sampler...

Hi all...

I've been looking for a way to sustain loop some very short samples (200.1ms). I've found some good starts from what I can find on the forum already, but haven't been able to get anything working as smoothly as the native Ableton sampler.

This is of course likely due to my incomplete understanding of how to make the most of these programs like Rez, Karma, or grooveduck2, but I am wondering if anyone could help to point me in the right direction.

in Ableton the setup I am using looks like this. The modulation is key to disguising the loopiness.

Am I on the right track by using Rez, Karma, or groove duck? I've also tried creating two instances of wave~ controlled by offset phasors/functions to window them.

I can get some of the things happening -- either the modulation or the reverse/crossfading, but I have yet to get it all working together as seamlessly as the Ableton Sampler.

Anybody have any advice for me? Which thread or program should I most likely be working with?

Thanks so much in advance!!!