So I followed your steps, edited the stats of a pokemon that was already in my party to 999 then set and export save immediately without viewing the edited party slot. But the stats seem to have reverted back to the original values when I viewed it in game. What am I doing wrong? @Kaphotics
Given that Latios/Latias seems to be independent from the one you own (as opposed to Surfing with a particular Kyogre in your party), I don't think it changes.
In current game version only phony forms can be obtained from raids, so there's no need for distinction. All future Pokémon forms will be handled in the same way (only when there are multiple forms actually available).
Yes, you cannot obtain three-segment form from tera raid directly (unless hax). You can obtain rare Dunsparce and evolve it.
Oh dear, that's very unfortunate. Anyway, tysm for the clarification.
P.S. I tested this on Pokemon Scarlet Violet for anyone who's wondering. You can, however, max out all EVs without any problems