1. No, "Sin" is in this context just a shortcut/enumvalue/channelset for Curve property @ 100%
2. Speedmode is a property of a StepRecipe and of the Stepcreator , use the Set keyword to set this property:
Set StepCreator Property "SpeedMode" "PerStep"
Set StepCreator Property "SpeedMode" "PerLoop"
Set StepRecipe 4 "SpeedMode" "PerStep"
Set StepRecipe 5 Thru 8 "SpeedMode" "PerLoop"
I'll just borrow the thread for a related issue.
Isn't the 'PerStep' in the StepEditor a bit misleading?
From what I've seen the number of steps doesn't really matter but the number of fixtures does...
Maybe call this PerFixture and add a PerStep that is based on the number of steps?
I believe this third mode could be useful too.