By creating a UTXO that aggregates other UTXOs, you would be able to greatly reduce the size of the UTXO set on the blockchain. This could potentially lead to faster and more efficient transactions.
However, this approach may lead to increased complexity in the verification process. In order to verify that a UTXO is valid and can be spent, the blockchain would need to verify not only the inclusion proof of the aggregate UTXO, but also the inclusion proofs of all of the individual UTXOs that make up the aggregate UTXO.
Can you make up a solution to this problem?
Keeping in mind these are all just pie-in-the-sky ideas at the moment, my theory is that similarly to how a prover of a taproot script only has to reveal tagged branches of the commitment to spend, the prover of an aggregate UTXO would reveal tagged branches of the aggregate UTXO. Such that they don't need to prove for any other keys or outputs except for the ones that are explicitly theirs. So in some sense this means the UTXO itself needs to be cryptographically encoded to retain these commitments.