When creating a Sustain Loop, changes we make to the loop points are not updated on the fly. But they are for Sample Loops. That is, you can set a normal Sample loop, begin the preview, and while the signal is looping thru the Sample Start and End points, you can change them and the playback is updated. (This makes it easy to create a clean, click-free loop.) But this same behavior does not exist for Sustain loops. So, if we want to make a clean Sustain loop (usually for vocal lines), we often have to create the loop in the Sample fields first, check it and clean it, then turn that off and re-enter the same values in the Sustain Loop fields.

To save time, we would like to see a little toggle button which simply switches the values between the two loop types. Or better yet, emulate the Sample Loop preview behavior in the Sustain Loop...