Extra event doors
This patch lets you to make grey doors flashing after certain event has happened without using room states. You even can be in the same room where event has happened to get effect. It's working like Dachora/Eticoons saved check because it's based on it with exception that any event can be used. This version lets you to use $100 extra events, $200 in total. Just in case if regular 256 events is not enough for you.

Warning
Read this if have used SuperMap patch, any version.
SuperMap patch already lets you to use every single byte in SRAM. So, there are no free space to use litterally and extra event array will use some space of item bit array. Actually, there will be a common space used by both arrays at $7E:D840. But this also has a cool side effect.

About sharing effect
Read this if have used SuperMap patch, any version.
Let me explain how this works. Collect item with index 012 (for example) and extra event 12 will be set and vice versa: set extra event 12 and item with index 012 will disappear without actually collecting it. And even more. Grey door with High Byte 38..3F and Low Byte 12 will start flashing after extra event 12 will be set or item with index 012 will be collected. To avoid this sharing effect, simply don't set indexes of the items that are matching extra events. For example, if you want to use $20 extra events (from $00 to $1F), don't use indexes for the items from $000 to $01F and use indexes from $020 to $7FF. In general, using X extra events doesn't allow you to use first X indexes from item bit array unless you want to use extra events as item events.