ABC Transcription Tools - Massive Tunebook PDF Torture Test (386 tunes)
While I wouldn't recommend trying to edit a 386 tune tunebook in the editor itself, you can certainly bring such a huge tunebook into the tool to print or export it to PDF using your browser's native Print feature.
It will take a while to initially render the tunes when you first load them, probably well over a minute, but be patient. After that you can view them and then access the print menu on your browser.
Took about 30 seconds for Firefox on an M1 Mac to export the complete PDF.
Chrome or Firefox recommended if you're going to try this. Safari on Mac didn't work as well.