While we are putting left field ideas out there, here’s mine;
We are asking people to do something that is very physically demanding, in a professional environment, yet we are not giving them the training, nutritional support, coaching and mental skills training that is widely used and available to even non-professionals who undertake physically demanding tasks.
I suggest that ULH pilots be given access to personal trainers, physiotherapists, and mental skills coaches. That they be rostered sessions with each of the above monthly and provided with weekly nutrition packs delivered to their front doors by ‘Hello Fresh’ or a similar provider.
If we want people to be able to perform extraordinary feats of endurance ( calmly managing complex rapidly developing emergencies with high consequences after being airborne/awake for extended periods of time) then why not treat them like we treat our sports teams? We know that our sports teams would be soundly beaten if we didn’t provide them with these things, let’s hope our ULH pilots aren’t soundly beaten when it really counts.
( If all that sounds too expensive then just gas up in Singapore and do a crew swap. That works.)