Right now you’re locked to only those you gain “standard” by leveling up. However, I and many other GMs utilize experiences in more ways than this one.
For example, a common house rule is “Negative” experiences related to a Scar that the GM can call on by spending a Fear- like fear of drowning or a particular monster-type. I personally also allow ultra-specific experiences if the PCs purchase books in my game-world or uncover ancient knowledge on specific topics. One of my players is even using a long-term downtime project to write a chronicle of the party’s adventures, and I’d like to gift that PC an experience that allows her to recall specific things about the game’s history that irl note-keepers might not catch, like obscure NPC names, the vibe off a twist villain, etc.
Hoping this is an easy add since the framework for experiences already exist. As long as positive AND negative modifiers are allowed I’ll be happy.