yeah they should at least definitely be playing an hour and 45 minutes... but 2 hours is the standard for most headlining bands.
i would love if they rocked it hard for like an hour and 15, then just Liam did his thing on the stage and played more cinematic Prodigy tracks for like 15-20 minutes. would be a nice breather. tracks like Weather Experience, Skylined, Climbatize, Medusa's Path (like a crazy megamix of em) and then close the section with Omen Reprise fading into IMD with Maxim, Keith, Leo, and Rob returning to stage and close it out with the heavy stuff again. but that's just my wishful thinking.
NIN did something like that during their Lights In The Sky tour. They had a section for the Ghosts stuff and everyone was playing instruments and it was a nice calm moment for everyone.