They will need deep pockets to make this work, I have done plenty of NATS with our lot and you are leaving the USA late evening at around 02:00Z with your body clock still in the UK meaning sleep prior to flight is difficult to achieve East bound.
Anyone considering this should put all times in Z think about what time you land locally in the USA do you eat have a beer then go to bed or go to bed and wake up Z time per your body clock? at say 8:00Z (03:00L) what i can say is that you will regularly be awake 20+ hours on the return trip and trying to go sleep during the day before your next trip will be a huge challenge, but worry not sleep with not be an issue when you get to your 7 days off assuming you live long enough on the drive home!!
I think you should plan on 3-4 days REST before you’ll feel half human again after which 5 earlier duties will seem like the good life you used to have, personally stop overs of less 24 hours should not be allowed, you’ll be back in the seat after what 18 -20 hours, legal but?