You can set the custom or idle pathway for the hands animation blueprint to animate a curl animation based on a scale or enum or something that you drive off of buttons sure. Both hands are the right model in the example as the left hand is mirrored in scale.
With the manny hands specifically they contain the skeleton for both hands in both sides so that isn’t really required, they can share the same animation blueprint, but things like the OpenXR hand tracking support would have to have a switch on it to use the left hand skeleton instead with the left hand.