I really would love to see such a comparison; especially by Tomato, who has done those perfectly before for other games.
Take a look at this: https://github.com/rofferom/seiken_densetsu_3
It can extract some Japanese text into picture files. With other language dumps we can help you probably. Magno would be a great support as well.
As Red already mentioned, we are currently investigating the official ROM as well. I am not sure what comes out of it. Text is not decoded yet. At least I would like to offer the official logos (compressed) for the existing fan translations as well. - Jezze might also create a “Trials of Mana” logo in the style he has done it with the “Secret of Mana 2” and “Seiken Densetsu 3” logo: http://www.romhacking.net/hacks/2569/
(*currently looking for the coordinates of "Seiken Densetsu" and "3"*; because different color palettes are used and we might need to tricky place the "3" (-> "of") into the middle of the screen.) Other spontaneous ideas: Including Neill's Music Test into the official ROM (there is way enough space), in a really long term - trying to compress official ROM (text) to 4MB, changing fonts, ...
Besides that, we will release the (final) German fan translation (v3.0) soon, since there is now the official release and I really don't want to see my latest changes go to waste... Too much work went into that. http://www.romhacking.net/translations/2037/
Better ask Terminus first, before making any tools public. Or share them privately with Tomato. Don't get me wrong, but asking doesn't hurt. Maybe they do not agree with this.
Please support Square Enix, buy this game – independently whatever you prefer to play (fan translation or Collection of Mana version).