Gen I SS Anne Departing Triggers + Save Flag Searching

[BERRY Guru]

Unless I'm mistaken, PKHeX currently lacks event flags for the SS Anne in its event editor. As such, I took it upon myself to find out what triggers are involved in the SS Anne departing from Vermilion Harbor. These are the different flags that appear on the SS Anne that I noticed in a memory viewer (all of which was done with US ROMs of Red and Blue):

(0xD803:0x00) The SS Anne remains in Vermilion Harbor.
(0xD803:0x02) When the Captain of the SS Anne's back is rubbed, this flag is triggered, and remains active while you talk to him.
(0xD803:0x03) HM01 CUT is acquired from the Captain. At this point, unless you lose to one of the Trainers on the ship on purpose, you can't leave the ship without it leaving.
(0xD803:0x07) As soon as you walk off of the ship, this flag triggers, and the SS Anne leaves the harbor.
(0xD803:0x17) When the SS Anne is finished departing, this flag triggers and the player automatically walks back to Vermilion City.
(0xD803:0x1F) This flag is triggered as soon as the animation of the player walking back to Vermilion is finished. The SS Anne is departed, and can no longer be boarded in normal gameplay.

Now, here are the oddities I noticed:

(0xD803:0x00) If you use a memory editor to reset the flag that causes the SS Anne to be departed back to 0x00, you can re-board the ship. However, the only thing that's reset is whether or not the ship has left. All the Trainers on the ship remember if you did or didn't fight them, and Blue isn't there to fight you. The only thing that controls whether or not the ship is ready to set sail is whether or not the player has received HM01 from the Captain.
(0xD803:0x02) Even though there's no point in-between you talking to the sea-sick Captain and receiving the HM01 where the game returns control to the player, the Captain being healed is its own separate flag.
(0xD803:0x03) If you were to enter Vermilion Harbor with this flag tripped, the SS Anne would remain in place until you enter the ship and exit it, at which point the address would read 0x07, and the ship would leave as normal. This is most likely the behavior the game exhibits if you black out to the Pokemon Center after getting the HM01.
(0xD803:0x07) If you were to enter Vermilion Harbor with this flag tripped, instead of the ship leaving again, you would walk back out immediately without even triggering the next flag, and it would skip straight to 0x1F.

And this is where things get tricky.

After editing the memory, I thought I might be able to edit the save files themselves to trigger the SS Anne returning. But I can't find the actual flags in the save file itself. If anyone could help find where this flag is, that would be appreciated.