(For any audience, see SPV in Thin client security.)Ok, well again, this is still SPV-like security(block depth). That's the definition of the security model. Practically you might feel it's ok, but it's certainly a different security model than Bitcoin full node security.
In that it is using block-depth it is like SPV (this I already acknowledged in a previous post), but it is not the same because of the extra information in the UTXO, and it is not the same as rolling-root/ledger-block because the current root is guaranteed to not have any relevant transactions prior to it.
Please be specific. What does the attack scenario look like with UTXO and/or ledger-block, and why does it require the full transaction history?
The wiki seems to agree with me actually:
Edit: Although it is saying something slightly different (shipping clients with the full UTXO already intact, but I don't think that's necessary with rolling root. Would have to give it more thought, but might not be necessary for UTXO either. If there's a problem for UTXO, it could be fixed with a rolling-root type solution).