Hi! ☺
I was facing the same problem and downloaded the Trial Version of Autokrama AutoCodecs. The problem is, its still incredibly timeconsuming to single-export or single-mark every trimmed clip in the timeline.
My solution was the workaround with Davinci Resolve, which is actually free…
1. You select your clips, put them in your timeline
2. You export the whole timeline to Davinci Resolve via Export -> Export Final Cut Pro XML
3. You Import them to Davinci and go to the Delivery Tab
4. In the export settings, choose “Individual Clips” and thats it, all your clips exported the trimmed version you chose in Premiere in under 2 minutes ☺
Cheers
Josh