You can do that now in your own node. Merkle tree is constructed in a way, where you can discard transaction data, and keep only transaction IDs, if you want to.
Also, if you want to keep track of the UTXO set, then you can keep just "txid:vout", to uniquely identify each unspent coin.
The Merkle tree permits pruning, but doesn't improve TPS. It requires you to download full transaction data before pruning which is a waste of bandwidth. And VOUT is just an index value. OGH is a checksum.