Is it possible to maintain existing time trim during a reimport?

When I re-import an animation which has been trimmed, the re-import process resets the time to match the source fbx. Is it possible to set the re-import process to maintain any existing time trimming? Here’s why I’m asking:

I’d like to update the skeleton for my character. But updating my skeleton will require me to re-import all of the associated animation clips. And my character has hundreds of animation clips associated with it, many of which have been trimmed in time, and now differ from the source fbx. Things like additive blendspaces for looking, which include 9 poses to describe looking up/down/left/right/etc… These 9 poses are created from a source fbx that includes all 9 in one clip. This is one of many, many examples where we chose to trim time on clips.