I find the Franklin model far more useful [...] because it gives you agency.
This sounds like me always complaining about "Past Me"'s tech debt. Or when tech debt is being introduced, my team jokes about it being "Future Me"'s problem. It's good for a chuckle, but obviously there is continuity of identity.
But continuity is not immutability. Your actions are a present thing, and define you in the present. Past actions may have consequences, but you are always free to act differently now. Likewise, your present actions don't carve a future identity in stone, either. "The rent is due everyday", so to speak.
We may be talking about two different things. When you say "Past actions may have consequences, but you are always free to act differently now.", I believe you mean that as in "just because you have ordered chocolate ice cream every time in the past does not mean it's impossible for you to order vanilla the next time", yes?
Whereas what I am talking about is "all of your past experiences, the circumstances of your birth, your genetic predispositions and the weather in Myanmar, have created a world-state in which you choose chocolate today. By definition, you will choose chocolate."
My point is that there is no "you" which makes choices in the present, independent from the circumstances which created it.
In that case, my choice to interpret myself as having agency was made, by itself, in the actual absence of agency. Neat!