As Centauras says, look for something simple.
Somehow before the flight the trim was moved to full deflection, during maintenance or preflight or kids in the cockpit or otherwise.
Pilot misses this due to interrupted pre-flight (as per video evidence) or lack of checklist (anecdotal evidence of this) or otherwise.
Power is applied, takeoff roll, control problems start, boost is off, pilot has never seen this before and the rest is history.
It’s a simple scenario that doesn’t require a complex sequence of events to transpire in order to explain, such as one specific trim cable breaking in the crash and then another being stretched or pulled straight after and the rudder trim being moved.
I can’t help but feel that a cable with a jack screw would need a firm and consistent pull to rotate the thread, possibly requiring both cables to activate, rather than a short sharp pull on a single cable, as the impact forces pulled on it abruptly. (Awaiting attachment approval above).
For a rollback scenario or friction issue, you’ve got too many things that add up to get to that end result, such as an engine failure / power loss AND the trim cable scenario has occurred? Plausible maybe, but unlikely... yes.
In option 1 above, only one thing has happened to cause the end result, not multiple things, working backwards from the end result.