Isn’t there any option to adjust speed of matinee play function like UDK in blueprint or Matinee ?
Anything except changing all of frames manually ?
To set play rate:
Select your Matinee actor > Right click in Level BP and Add reference to that Matine actor > drag from it > type Play Rate and you’ll get set play rate node.
To stretch keyframes:
Select the keyframes you want to modify in a track > Edit > Stretch selected keyframes; or set the duration you want to stretch with green arrows > Edit > Stretch Section.