ARA2 Melodyne comping, how to crossfade

Really pretty unstable actually. Crashes and loooong lags when any ARA2 tracks are being edited. “Bounce selection” of a 10 sec clip took about 7 minutes! (But it did render the melodyned data.) Render in place was a crash. This appears not ready fr prime time…
Anyone have any help for me on crossfades?