As with Captain Marvel when trying to convert Avengers - Endgame the process occurs glacially slow when down-converting audio. Previously, with Captain Marvel the slow process occurred when converting or keeping the original DTS-HD 7.1 audio. Apparently when keeping the original audio the processing slowdown has been resolved in CloneBD 188.8.131.52. When keeping the original audio Avenger's Endgame compresses to BD-25 very quickly. No such luck when down-converting, however. Avengers - Endgame took over 3 hours at ~21 fps when converting DTS-HD to AC3 5.1. Logs attached.