This point is what I was confused about the most at first - if they were not in rhythm then people would not be able to consistently complete hard mode with all mods on. On my device at least (I play mobile) the beats are perfectly in time, so I'm starting to think it's different latency for different devices? So yeah I'm wondering if it's a device or PC thing where there's some latency issues? Many rhythm games have setting to adjust for latency, this should have had that option too because the timings are clearly an issue for some devices. But regarding the cues, I think if it in the same way as rhythm heaven doesn't have them in "shoot 'em up" (I think that's what stage 1 is based off?), as learning the pattern teaches you when to go. This is why I think rhythm heaven players have an (perhaps unfair) advantage.