Unfortunately, the design doesn't allow for new full nodes: "Now the new user asks an existing user for the UTXO set for the ledger up to level `−e. The user c

Unfortunately, the design doesn't allow for new full nodes: "Now the new user asks an existing user for the UTXO set for the ledger up to level `−e. The user can verify the correctness of this set by comparing it with the UTXO set commitment stored in the leader block at level `" That's not verifying that there's a valid history leading to this UTXO set, that's just trusting other nodes when they testify to that.