Picked one up for Christmas and have already been having a blast with it today. Yes, it is supremely hackable, try awesome-flipperzero [1] as a starting point. The iOS exploit discussed here is already patched as of a week or two ago, fwiw.
Like, I classify myself as an empath, and it's physically painful to think about using it and having to face the dolphin's sad face if it's been a while.
Looks like I need to hack mine to not get sad when I don't use it. Digital antidepressants, as it were...