My issue with vitalik’s new take is it normalises rolling back the chain. “Oh we’ll just roll back the chain like we said we would” … quantum emergency y’all 

But if you do it for one thing you can do it for everything. Soon even polkadot will be asking … what about 4448 et al

 Is there no better way?

If we fully switch to account abstraction then I would endorse "no rollbacks even in a quantum emergency"

My concern was from a legal standpoint; potentially leading validators, especially the bigger ones, to great risk

Isn't it understood even in bitcoin that a quantum emergency could justify hard forks and arbitrary crazy actions to protect people's money?

Though I guess in bitcoin the rules are that arbitrary rollbacks are potentially permissible if majority of miners can be convinced to go along with them?