If you were a warlock with say four dots.
Each dot had the same duration.
You could have /castsequence reset=mod:alt Corruption,Null
And the like for each.

I've not messed around with reset on modifier keys, so am not positive if that is the correct syntax even.
But I'd assume, a reset as a mod key would then reset each sequence, resulting in another cast of each.

In the case of actual wow, pretty much any class, we have different timings on ideal recast.
For example Lava Burst cannot be cast more then once every 8 seconds. So we want enough comma's in there that is doesn't get stuck trying to recast while its on cooldown.
Or Flame Shock lasts 18 seconds before it needs to be recast, so there's no point in recasting before then.

If there was a reset condition such as the Alt modifier key, we'd be reapplying Flame Shock even while its still up, or Lava Bursting every 18 seconds even though we could recast after 8.

So technically, you could use a reset condition in the place of comma's.
But in practice unless every ability in the click sequence had the same desired refresh there would be no point.