I've been going through some of my older saves recently, preparing them for transfer into HOME. I've managed to wrangle most of the Pokemon into states that PKHeX recognizes as legal, but there are some edge cases that I would like to examine:
1. Encounter Slot Legality
I previously edited some Pokemon without knowing about the PID/IV correlation mechanic. Most were fixable, but I couldn't find appropriate encounter slots for some spreads that could be hit with the proper H2/H4 methods. PKHeX still marks these as legal, so does that mean the HOME legality checker disregards encounter slot mismatches?
2. Egg IV RNG in FRLG vs RSE/HGSS
Guides on this site recommend setting the encounter type/met location as hatched from an egg for generated Pokemon to avoid a whole bunch of PID, IV or location mismatch issues. But isn't that only the case for Emerald or HGSS, where the RNG calls to generate PID and IV are made independently upon pickup and hatching? I assume that for FRLG there is an undocumented correlation between PID and IV even for Pokemon hatched from eggs. So is it better to avoid breeding in FRLG altogether, or if I really wanted a specific genned PID/IV combination might it be best to "trade" the egg over to Emerald to hatch? Would I have to set a Hoenn met location in that case?
Or is the reverse also true, where any breeding by FRLG-exclusive Pokemon could technically have been done in Emerald by trading over the appropriate parents, before sending the egg back to FRLG to hatch? Thus, taking advantage of Emerald's broken RNG, but with appropriate Kanto location data? Is that why PKHeX doesn't enforce strict PID/IV correlations for hatched Pokemon in FRLG?
3. Ability Slot upon Transfer
Even when a Pokemon has only one ability, its PID still distinguishes between two ability slots. But when I passage some of my Gen 3 Pokemon up to Gen 4, they all default to their first-slot ability from Gen 3. When I try to change their abilities to match their slot value, PKHeX marks them as illegal. Are all Pokemon transferred between Gen 3 and 4 set with their original ability, regardless of if they gain a new ability for their second slot upon evolution?
For example, if I transfer a Shroomish (2) with Effect Spore from Emerald to HeartGold, will it evolve into a Breloom with Effect Spore (1) or Poison Heal (2)? To make it more complicated, Numel gained Simple, while Camerupt gained Solid Rock instead. Previously all Numel had Oblivious and evolved into Camerupt with Magma Armor. If I transfer a Numel (1) with Oblivious, I expect it to evolve into a Camerupt (1) with Magma Armor. But will a Numel (2) with Oblivious evolve into a Camerupt (2) with Solid Rock, or as a transfer Pokemon with Oblivious is it restricted to Ability Slot 1 as the default slot for Oblivious, evolving into a Camerupt (1) with Magma Armor, even if its PID should correspond with Ability Slot 2? Bulbapedia says that a recalculation should occur upon evolution, but I don't know if PKHeX implements this correctly.
4. Cute Charm IV Spreads
I used Cute Charm to obtain an Adamant 6IV Scyther with PID 00000099 from the Bug Catching Contest. This is accepted as legal in PKHeX, but such a combination cannot be reproduced with PokeFinder. As there is a limited number of Cute Charm PIDs, is there a list somewhere of the best corresponding IV spreads? Or does Cute Charm completely break the PID/IV correlation, only being relevant for expanding the range of shiny Pokemon can be found for the same TID?
5. Nonstandard Method Spreads with Flawless IVs
Due to algorithmic limitations I understand that only certain natures can be associated with flawless IVs in Generations 3 and 4. However, using PokeGen I'm able to find the following PIDs that have perfect IVs, albeit via nonstandard generation methods that I've literally seen nowhere else:
Can anyone knowledgeable about the mechanics explain which types of Pokemon can be legitimately generated via these methods?