With this patch, pressing A, B, X or Y while on a level tile in the overworld will activate, respectively, the normal exit or secret exits 1, 2 and 3 and run the corresponding event instantly.
The patch includes a table of which events are allowed to be ran for each level (which is useful for contests/a showoff), but for actual debugging purposes, it's possible to circumvent that table and allow any button press to run any event in any level tile. The table also allows for specified levels to be enterable as normal.
This patch can be very easily removed from your hack.
The author removed the !check since they deemed it was too nieche to be fixed while also having not much freetime. Other then that, this patch is truly one of the best patches when creating a hack since you'd otherwise need to add in goal for every single level.
Edit: You can also enter destroyed forts and castles with L+R. Just keep this in mind if you build a presentation-only overworld. You can easily disable this behaviour in Lunar Magic so no patch required.
In addition, the special event colours will not be activated with this patch since it is dependent on the beaten level, not the event triggered. It might be good if the author adds such an option for the next version.