Ah, I see! Good to know the difference It definitely matters to me, yes, but since I'm used to get Mew on Red via the well-known glitch anyway, my inhibition to get it in FireRed via some ways of cheating is lower than with other pokémon ^^
I don't want to simply create one via Editor though because that would be kind of lame to me (changing the 'natural' IVs or so). I will try to catch one in Emerald on Faraway Island that has some good IVs by rng even though that might take some tries. 2-3 days ago I caught Mewtoo in FireRed and resetted my game save everytime I didn't like the IVs. It took around 150 tries until I got one with beautiful numbers: Modest nature, 31 HP, 31 Special Attack, ~29 Special Defense, ~25 Speed, Phys Attack was ok, Defense 0-1 though I hope the resetting didn't hurt the cartridge in the long term.
It feels good to know that FireRed has no internal battery that can run dry one day. I was so unhappy when my Gold Edition with all 251 Pokémon was deleted. Must have been 10 years ago or something. Since then I didn't give Pokémon another serious try with the exception of buying HeartGold and playing it a few hours.
Will check out the other tickets later. Just took a look at what Glitzer Popping is and it sounds complicated but quite interesting. Didn't know any glitches in Gen 3 till now. Oh and thanks for showing me Bulbapedia! I only knew the german PokeWiki but Bulbapedia seems to have many more useful articles!