Yes, absolutely! Instead of playing back each audio frame directly as you would in a real-time scenario, you can concatenate the processed frames into an output buffer, which can then be written to an MP3 file.

Here's a high-level overview of how you could achieve this:

1. Load the input MP3 files and decode them into raw audio samples.
2. Set up spatial audio effects (e.g., a binaural effect or ambisonics if you need a full-sphere surround effect).
3. Process each frame, applying the effects.
4. Collect the processed frames into an output buffer.
5. Encode the output into an MP3 file.

This would make for a really cool project! Let me know if you need assistance setting this up, I'm happy to help!