Snap Datamine Notes

Pokémon Snap Data Notes:
Based on the data from the dumped Rom online and my own rom dump, I can confirm CC's theory on the map load seed RNG.
When the map loads, the software generates the seed, and regenerates the seed when the map is exited and reloaded. Only thing to note is that it is done indepedently of the system hardware or emulation, and is done purely by the game itself.
That being said, it would make it extremely complicated to manipulate the RSG to create a viable manipulation for the spawns.
So many things come into play when the game pulls information from the seed that you would need to already know the seed, and know exactly how to lag out the frames, and input button commands to change it to exactly what you need.
Unfortunately, I can't see any kind of viable way to actually do that, given the seed itself is completely random, and it's unrealistic for someone to figure out the seed and manipulate how the game draws on it without actively looking at emulation data.
The only interraction I can find that really effects the Cloyster is simply throwing things at it once it is spawned already, which provides nothing towards your goal.
Furthermore, this applies to most every variation in the game from what I can tell, with little exception.
I can find no evidence to support a theory of manipulation of Pikachu's animation cycle, unfortunately, as this also stems purely from the game's random seed generation. Given the seed is generated at the start of the level, and proves itself to be random, the position of pikachu on the main menu technically has no bearing on the seed generation. There is no reference to the timing of the menu that overrides the Seed's priority either.
Were the seed in a permanent state of flux in the menus, with values constantly changing and then locking on the frame the software loads the map it would be different, and things such as pikachu's position from the menu could theoretically be used to increase chances, if we knew the exact time it took us to get from Starting the file to the frame that the software locked the Seed, but this is not the case.
This holds true for all examples requested of me to research. Lapras, Butterfree, Charmander, Magmar, Growlithe, Arcananine, Dratini, and Goldeen are all subject to the same random seed generation system. With the minor exception of Weepinbell. Oddly enough, while it does behave based on the seed, it has a lot more leeway in what seed data strings trigger it to start and stop. To put it succintly, he simply has a higher chance to cycle his behavior.


Side notes-
Difference between cart's speed at key points in Japanese rom dump enigmatic. Can't find a reference to why it would do so, but video evidence is irrefutable.
English score check text appears to be faster due to better optimized coding present in the international release, assumed to have been done by a programmer when bugchecking and localizing.
Side request seems impossible without the introduction of a game breaking glitch that is yet unfound. The triggers that activate the item based pokemon in stages appearing before the aquisition of the items are not able to be recreated by anything you would have access to at that point. Barring a game breaking glitch being discovered that allows a null item occupying the same data slots as the Flute, apples, or pester balls. While it is certainly possible for the game to create such null items, I cannot find a way of introducing them to the game without save data modification or direct manipulation from third party hardware, and such things would be volatile to the game's stability, and the longevity of the physical cartridge.
Red dot emulation bug present is because of constraints on the rendering system excluding the software from recognizing color pixel patterns.

Information collected from my personal English Rom Dump directly from cartridge and a Japanese Rom Dump from EmuParadise, information stemming from information found on Japanese rom credited to their editors and publishers for providing the rom.

RNG- Random Number Generation
RSG- Random Seed Generation/Generator
Cart- Referencing the in-game vehicle, not the physical Cartridge