There should be something in the overall experience to indicate speed changes. Combospam is some people's way of expressing sudden changes, but it's kind of bogus because it's not immediately clear that a speed change is being expressed.
If a speed change is subtle enough that it doesn't screw up many players, then it's not really a problem in the first place. If it isn't subtle, then there's a good chance that it will and if we go by something like Garven's example, changes in tick density will make speed changes at least remotely easier to anticipate.
Even rules can be broken in special cases, if the song/mapping really call for it, so people could still circumvent this if they have a strong enough case. Even if this isn't agreed on as a tick rule, I'm sure it can be agreed that having sliders of different speed, which look the goddamn same, are stupid. Perhaps that aspect could be incorporated instead?
If a speed change is subtle enough that it doesn't screw up many players, then it's not really a problem in the first place. If it isn't subtle, then there's a good chance that it will and if we go by something like Garven's example, changes in tick density will make speed changes at least remotely easier to anticipate.
Even rules can be broken in special cases, if the song/mapping really call for it, so people could still circumvent this if they have a strong enough case. Even if this isn't agreed on as a tick rule, I'm sure it can be agreed that having sliders of different speed, which look the goddamn same, are stupid. Perhaps that aspect could be incorporated instead?