Mechanics Bugs "Priority Queue"

Most important to Gen 7:

1) [HARD, UNSURE WHAT IS CAUSING THE BEHAVIOR] Deterministic Speed tie behavior. There's a wealth of examples in the bug reports thread around the area, Perish Song was just one example. https://github.com/Zarel/Pokemon-Showdown/projects/3#card-24732298
2) [HARD, COMPREHENSIVE] SadisticMystic research implementation. We have an onResidual for end of turn effects; I'm not sure if there's something comparable for how checks are done prior to move success, but it really could use one. It would help smooth out a lot of interactions and hopefully help in the preparation for SwSh where more will inevitably be added. https://www.smogon.com/forums/threads/ultra-sun-ultra-moon-battle-mechanics-research-read-post-2.3620030/post-8096570.
3) [MEDIUM] Unaware's bug with spread moves. https://github.com/Zarel/Pokemon-Showdown/projects/3#card-25870229
4) [MEDIUM] Forced slot switching. Slayer started on it but never finished. I don't care if we have client support for it, just force it to go to left slot. https://github.com/Zarel/Pokemon-Showdown/projects/3#card-23557361
5) [EASY/MEDIUM] Pursuit's interaction with Volt Switch / U-turn; should take damage, then user should be prompted to switch. https://github.com/Zarel/Pokemon-Showdown/projects/3#card-24732140
6) [MEDIUM-POTENTIALLY VERY HARD AND COMPREHENSIVE] - OZY damage formula stuff, making sure that damage is called using proper modifier order for Gen 7 (since some stuff is different from Gen 5). See https://github.com/Zarel/Pokemon-Showdown/projects/3#card-25870312, also my comprehensive article on the topic: https://www.trainertower.com/dawoblefets-damage-dissertation/
7) [MEDIUM] Confusion damage should not cause Berries to trigger. This was working correctly at one point, but something broke it. https://github.com/Zarel/Pokemon-Showdown/projects/3#card-23723649
8) [EASY] Z-moves of moves that called other moves should display the called move. https://github.com/Zarel/Pokemon-Showdown/projects/3#card-23557676
9) [MEDIUM] Hazards should trigger in the order they were set up (like a queue): https://github.com/Zarel/Pokemon-Showdown/projects/3#card-23557574
10) [EASY] Cursed Body should be able to roll on regular/exclusive Z-moves. https://github.com/Zarel/Pokemon-Showdown/projects/3#card-23557453
11) [EASY] Synchronoise should check all targets individually for damage: https://github.com/Zarel/Pokemon-Showdown/projects/3#card-23557605
12) [MEDIUM] Leech Seed + Ally Switch interactions: https://github.com/Zarel/Pokemon-Showdown/projects/3#card-23723879, https://github.com/Zarel/Pokemon-Showdown/projects/3#card-18661472
13) [EASY] Natural Gift should respect Primal weather https://github.com/Zarel/Pokemon-Showdown/projects/3#card-23723732

Likely to come up in Gen 8 (all non-Z-move behavior from above is likely to come up in Gen 8 too)
1) [MEDIUM] Berry interaction with Unnerve -> Unnerve; likely going to be similar behavior with the new Galar Weezing ability, best figure out Unnerve now. https://github.com/Zarel/Pokemon-Showdown/projects/3#card-18659708
2) [MEDIUM-HARD] VGC timeouts should respect previously chosen options: https://github.com/Zarel/Pokemon-Showdown/projects/3#card-23723592


[MEDIUM] The only major client bug that leads to mechanics errors is with Transform needing to reveal Abilities, which is the same bug as Skill Swapped abilities in doubles not working properly. See https://www.smogon.com/forums/threads/ps-serious-bug-reports.3521891/post-8236147