I might not have said anything back in the day, but now I will. There's a weird insistence that people seem to have with just tricking the timer and whatever lowest value you get is acceptable even if it's not really the fastest. People figured out that the timer in Chaos 0 starts later in adventure mode, allowing you to get a better time (that doesn't get saved to your Trial charts no less) even though you're not using the real fastest strategy. What's the point? Why limit the strategy by not having the light speed dash and do it an actually slower way? This is when you should have a rule for such instances. Keep it about being fun. About finding and using the fastest strategy, not about figuring out that adventure mode calculates time differently.
Now there's a new strat in Casinopolis to completely freeze time by talking to a hint monitor. So it's no longer about finishing the stage as fast and possible, but just how fast you talk to this monitor that's right next to you. Sure, there's some skill involved in that too, but I find the whole concept of limiting the scope of a challenge this way inane.
When I discovered how to get to a new capsule right at the start of Final Egg, I was disappointed that the stage got so much shorter, but I accepted it because it was still about completing the stage as fast as possible. It wasn't about playing with the timer. When it was discovered how to skip the snowboard in Ice Cap, which let's you finish the stage with the timer frozen, it felt weird, but I accepted it because the frozen timer was a direct result of using a huge shortcut that really does make you finish the stage in record time. Like topic title says, the fun of time attack is all about finishing fastest. If you trick the timer in the process, then so be it, but when doing so means it's no longer about finishing a stage in record time, but only about an on-screen timer, then that's when it's time to consider establishing a rule.