They said in another thread that they were working on making it more difficult to bypass the trash mobs.
Praetorium has a few groups of mobs that are easy to skip past, but you only gain about 5 minutes skipping all of them. If any adjustment is needed it's to simply give the mobs a a wider field of view, cause right now you can pretty much approach them at a 45 degree angle away from forward and they won't even see you. 25 minutes or so per run with non-DF, about 45min DF.
CM is already hard enough and the only way you can fail it easily is if you have weak tanks or laggy healers. about 60min DF.