So, when I tried to listen to music with earphones by inserting a previously purchased USB Type-C mini-jack conversion adapter that was sold as compatible with high-resolution sound sources into the iPhone 15 Pro Max, it recognized the adapter.
Just to be sure, I tried it on XPERIA 10 III and got the same result (note that you can directly plug in earphones to XPERIA 10 III).
Please note that some USB Type-C mini jack conversion adapters may not be able to be recognized by iPhone or XPERIA.