To some degree, JLB is stuck between a rock and a hard place. When you look at the YT comments, people are pretty damn critical of James' vocal performances. But at the same time, when you look at the video of LTL, people stand up and cheer at the F# (well, F). So, from DT's perspective they see that the fans are kinda Pavlovian dogs that need to hear an F#, otherwise it wasn't a good concert for them. I think that may also be the reason why they keep inserting these high notes on their records, despite knowing entirely well that James will struggle with them live.