I don’t use the trimmer to trim. I simply put the clip on the time line, and work on it there. I simply collapse, or roll, the clip back to my first starting point. Then I snip the clip between my first ending point and my second starting point. I can then roll the ends from the snip point to the first ending point and to the second starting point. If I subsequently want to extend the “sub clips”, I can simply roll the ends out as far as necessary. No trimmer is necessary, and I can copy and paste just as I would with trimmer clips.