Poor darlings exhausted if less than 50 hours slip, more like "if I can't shop and party for 50 hours then I'll have a hissy fit". Get used to 38 hour slips.
With the Vaus arrival time of 0700 LAX by the time you get to the hotel it will be early AM time back home and the body will be ready to sleep. After a few hours sleep you will be up and about till later that night LAX time. Best time for sleep is from about 0400 LMT LAX and you will sleep through until about 1400 LMT LAX easily. Then up and about for a few hours then off to work at around 2030 LMT LAX.
You will get plenty of sleep in the 2 sleep periods, you will not be exhausted. As soon as Vaus have the aircraft to make it a daily service, you will be on 38 hours slip. There is absolutely no fatigue modeling that will justify otherwise. Get used to long haul flying, its about many time zone changes, sufficient rest to have you safe for the return flight, and nothing else.