Great, thank you so much!
So! I'm not sure if this is going to work for you or not, but I have found one possible solution. It involves firing 2 tweens at the same time and effectively switching between them by lerping to the value of the desired tween. It's a bit funky, but it might do what you need it to. Do note though, that both tweens should use the same duration for this trick to work best. Here is a link to an example project. The code is in obj_Example. When running the example, click the left mouse button to toggle between the 2 tweens.
Let me know if this helps at all.