@heunland made a fantastic discovery, which is that some swapping services already support swapping STORJ to USDC on layer 1 if you type in the STORJ zkSync contract address directly.
For instance, if you go to Jumper | Multi-Chain Bridging & Swapping (powered by LI.FI), and enter 0xA0806DA7835a4E63dB2CE44A2b622eF8b73B5DB5 as the zkSync token contract address (that is the address of the STORJ bridged token), you should be able to do a swap.
This screenshot is after I entered 0xA0806DA7835a4E63dB2CE44A2b622eF8b73B5DB5 in the “From” field:
