Oh, also I figured out the problem with reversing clips in Kdenlive... turns out if the source clip is messed with prior to import, the editor doesn't like it. I did noise reduction on an audio rip prior to importing it and attempting to reverse it, and Kdenlive output a bunch of glitched static. Just putting in undoctored audio and reversing it puts some obvious strain on the GPU during replay in-editor, but once rendered it comes out just fine.