Most of my recordings are concerts. I'll pull my recording into Avidemux, trim it & then just re-mux it. Then I'll pull the re-mux into Vegas, sync up the 24-bit soundboard & render out the audio only. Then the re-mux & synced up board go to mkvMerge where I assemble everything. As long as I don't need to fix anything on the video track, I never touch it or re-render it.