Hopefully this brings me back to modding the game, but I doubt it... but it's worth a discussion.
I did try this once before, and I forget if it worked out (I did this on the real console), but I never looked into it deeply.
Here's some baseline stats for your reference:
Crystal Armor/Crystal Mail
--------------------------
Defense Power: 25
Evade Rate: 0
Magic Defense: 10
Magic Evasion: 6
Stat Modifiers: +3 Will
Elemental: n/a
Status Immunity: Toad, Mini, Piggy, Silence/Mute, Blind/Silence, Berserk
Resistant Against: Undead
Metallic: No
Equipped By: Paladin Cecil
Value: 10
Notes: This is found in a treasure chest filled with monsters in the Lunar
Subterrane.
White Robe
----------
Defense Power: 18
Evade Rate: 10
Magic Defense: 10
Magic Evasion: 6
Stat Modifiers: +15 Will
Elemental: n/a
Status Immunity: Blind/Darkness
Resistant Against: Spirits/Ghouls, Undead
Metallic: No
Equipped By: Young Rydia, Tellah, Rosa, Porom, Paladin Cecil, FuSoYa
Value: 10
Notes: This is not really a great upgrade for Rosa, particularly when it comes
to Magic Evasion.
I have long argued that the Minerva/Heroine Robe was better for Rosa than the White Robe.
I've long held the belief that evasion in this game is far more important than raw defense (not that having both is a bad thing), so when it comes to heavy armor like the Diamond Armor (defense) vs the Sorcerer/Light Robe (evasion, magic defense, magic evasion, stats), it's not as bad as one would think.
I believe Cecil is best served with this armor... not only will he have the ability to do better healing early on, he will be more effective at evading AND the most important aspect is that he is not immune to Berserk status. The other resistances can easily be covered with a Ribbon anyhow.