Hey, the best option is to make a scene director dedicated for NLE that plays in and out, it needs to symmetrical and what we do is basically hold / stretch the middle key from of the length of the animations. For example, if your entire animation is 60 frames we will always hold the middle one so you're in should be 30 and out should be 30. However, they don't have to be exactly the same. For example, if you're in is 30 frames and your out is only 10 simply take the out 10 frames to frame 50 and this will make the total length 60 frames.
#XPression