Would this work for you:
- the TL length is 80s
- you have your regular 0-1 alpha float
- and you have 2 Event Tracks (Speed 1, 2) kicking in at specific seconds Time and set a variable
- actors sliding along the spline use this value to move faster along it
This way you no longer need to fiddle with Play Rate, and the TL last precisely 80s (because you do not fiddle with Play Rate).
I might’ve misunderstood the intent even though your description is pretty spot on. Do tell.
This sounds a bit like this a rollercoaster? A cart in mine?