i think that replacing is a good thing but versions of events that sounds like an even better solution

diffs are a good intermediate for minimising data but they need to be checkpointed and being events they have to be signed by the authors so any protocol involving diffs needs to also consider checkpoints...

hey, there's no reason why checkpoints can't literally be collections of the whole original and it's modification chain, that can be a meta event type that wraps them into a bundle, doesn't require any signatures but it's not an event