I’m not sure if this will be practical or if it will work at all but maybe you could have a loop which is like this
-Start the montage with the speed you want
-Enter the loop (which breaks when the montage is no longer supposed to run)
-Set Play Rate (using a float variable)
-Increase the float if hasn’t reached a certain amount (the cap for the speed)
-Repeat the loop
I don’t know if you will need to put delay somewhere (maybe before/after the Set Play Rate) but that’s my idea. Actually I’m not even sure if you can make loops in the animationBP or if UE won’t crash with infinite loop since it did the last time I tried to make a similar loop.
Edit: oh well seems like you tried it already and it crashed for infinite loop like I suspected. I’m kind of interested in why this crashes myself as I was making some loops last week and they ended up being infinite even when they clearly had an end.