Reverse Keyframes in Premiere Pro?

I created a few transitions as custom presets. But now I want to make an exit transition version for each one. I assumed there'd be a reverse keyframe option like in After Effects but it's not here.

Does anyone know how to reverse the position of multiple keyframes in Premiere Pro? And does anyone know of a plugin, custom mod, etc. that can do this?

**NOTE: Before anyone links/mentions it, I did see an old thread about reversing keyframes, but the solution does not work at all. Basically it said to: Create a dummy image/clip, nest it, copy-paste the keyframes on the nested sequence, and reverse the nested sequence to see the reversed keyframes. However, if I make a preset of the "reversed" effect, its keyframes are automatically un-reversed and put back to normal by Premiere. So if I drag the new preset on my intended clip, it'll just behave the same as the original preset I intended to make a reverse of. And even if I manually copy the reversed keyframes from the nested sequence and paste them on a normal clip, the keyframes still un-reverse themselves.