From what I understand, Pluton is more in the vein of TPMs, so able to store and handle your cryptographic keys and to do measurements during your boot process.

From what I understand, Pluton is more in the vein of TPMs, so able to store and handle your cryptographic keys and to do measurements during your boot process. SGX is a hardware feature that allows an app to run securely (i.e. Without any possible interference from other apps or even the OS) in a hardware-enforced enclave. Completely different tasks and use cases, which might overlap - maybe you can use keys with Pluton from within an SGX enclave?