To have something be triggered over a single frame in Timeline, though, Unity recommend the use of a Signal rather than a dedicated Track type.
Signals are a somewhat complicated solution to the problem of calling events in Timeline (see Unity's docs on it here), but the code on the AC side of things is quite simple. Any ActionList (scene or asset-based) can be run by calling its Interact function.
Comments
It could be done through a custom script, yes.
To have something be triggered over a single frame in Timeline, though, Unity recommend the use of a Signal rather than a dedicated Track type.
Signals are a somewhat complicated solution to the problem of calling events in Timeline (see Unity's docs on it here), but the code on the AC side of things is quite simple. Any ActionList (scene or asset-based) can be run by calling its Interact function.