When creating a tween with VRCTweenHandle.SetSpeedBased() , there is no way to call VRCTweenHandle.ChangeEndValue() and have the tween refresh its duration. This is due to the fact that internally dotween doesn't call Tween.DOStartupDurationBased() within Tween.DoChangeEndValue() unless a duration is specified - because VRCTween doesn't provide a duration, it calls it with -1, which means that it never calls the duration update. Additionally, because VRCTweenHandle.SetDuration() sets the duration directly via reflection, there is no chance for it to recalculate the tween, and VRCTweenHandle.SetSpeedBased() - and thus TweenSettingsExtensions.SetSpeedBased() - this only sets it so other hooks update their values, which means that the value is never propagated. This renders speed-based tween values useless for continuous motion. Sample code to prove it: class Blah : UdonSharpBehaviour { public float value; private VRCTweenHandle _handle; public void _FadeUp() { _TweenTo(1, 0.1f); } public void _FadeDown() { _TweenTo(0, 0.1f); } public void _TweenTo(float target, float speed) { if (_handle.IsActive) { _handle.ChangeEndValue(target, true) .SetDuration(speed) .SetSpeedBased(); } else { _handle = VRCTween.TweenFloat(value, target, speed, this, nameof(value), "_DummyCall", VRCTweenEase.Linear) .SetSpeedBased(); } } } If you trigger _FadeUp and _FadeDown, you will see that if the tween is not freshly created, it will result in it ignoring duration. No matter how you change the ChangeEndValue branch (aside from recalculating the values yourself) you will see it will never result in a consistent transition speed. SDK version is worlds 3.10.4, unity version 2022.3.22f1
