How to preview animation transform in the viewport?

Hello guys, I’m using UE4.20.3 and I have met a problem about transforming the imported FBX animation sequence…

Now the problem is:

When I change the values of “import translation” or “import rotation”, the animation in the viewport won’t transform. Only if I click the “Reimport Animation” will the transform applied to the animation. If I select the root bone in the skeleton tree, and transform it in the viewport, it has nothing to do with the actual animation played in the game…

Now when I want to tweak two sequences of animation to have them connected smoothly, I have to try the transform parameters first and reimport the animation to see the effect, which is inconvenient…

So is there a way to preview the transformed animation in the viewport in real time?