I just published the full SwiftSync write-up.
It contains more details about the hash aggregate, and answers the following questions (and more):
- How exactly assumevalid is utilized and what the implications are
- How we can still check for inflation when we skip the amounts with assumevalid
- How we can validate transaction order while doing everything in parallel
- How we can perform the BIP30 duplicate output check without the UTXO set
- How this all relates to assumeutxo
To my knowledge, every validation check involving the UTXO set is covered, but I’d be curious to hear if anything was overlooked or if you spot any other issues.