If your threat model includes someone with a quantum computer intercepting all of your traffic and storing it to decrypt later, you probably don't want to share your keys over a non-PQC channel unless you can guarantee that they haven't started eavesdropping on your traffic yet.
While sntrup761x25519-sha512 is a QC secure key exchange, sending a key over it doesn't count. It's not really a "pre-shared" key unless the sharing is done using organic, locally sourced sneakers. Unless FIPs, and then it's boots.
