Able Ability System Info and Support Thread

How would I go about instantiating a Context / Ability with additional / pre-set variables? Currently, I need the Player to be able to set the Target beforehand, which would work in a Singleplayer environment since I could just retrieve it from any Blueprint. Looking at 3.29, this should be possible now? But I also cannot renounce client-side prediction. What’s the reasoning for Replicated Instances to break prediction?