Speed Effect on Meta Strips

I had to adjust the framerate of a video with the speed control effect in the stretch mode, and then, for me to be able to split the strip, i had to group it into a metastrip. Then, after that, i wanted to adjust the speed of some of the cut strips. I applied a speed control effect again in stretch mode, but it doesn't behave the way it should, considering only the slice of strip, but it outputs the whole unsliced strip inside the metastrip stretched squeezed into the frames of the slice. What do I do? If Blender only could adjust the speed of a clip inside the clip properties...