I think that the bridging solution is the safest and smartest way forward.
For the Federation/DeFederation conversation I really think that both sides have become too personal. Regardless of clandestine meetings or whatever - we need to operate from the position of -
"Hope for the best, make plans for the worst".
Best case scenario - they settle into the Fedi along with others. Sure we can hope for that.
But we need to assume that the potential for harm exists. We have to assume that the potential for bad admins exist. We have to assume the potential for #EEE (though I don't believe it works) will be attempted.
We need to consider these potentials and design accordingly. There is a risk here, and we need to think through things wholly.