As for main_menu, BAC9-FLCL says it is an ancient technique predating the knowledge of events.
Can we get a hint on those events then? I currently can't imagine running a code by button with the help of events. I use the sleeping bag menu to collect coordinates, but there should be a vanilla function to start the code.
Note that the formatting is messed up in some of those code snippets. You can get the Zone Reclamation Project which already has this code in various forms: The 1.05 test releases have the ability to continuously display this position info on-screen (better than rs_stats) and to echo your position to the console log on demand via Esc P, and there's a teleport feature that can make use of this info dynamically for testing, and you can preserve the jump points you record in _custom_zrp.script, and there's the anti-rad pseudo-hotkey code as well.
I will try to gain more experience with PPE in the next days and see if i can make some things even clearer. So far I only managed to make cool PPE effects accidentally. But that's already better than getting CTD by wrong HEX edits.