Need help with Kruptar (can't insert Battle Messages)

There is a SECOND set of text that ALSO appears in the narrow box at the top, called from spell effects, or the end of battles, etc. that I don't think are in FF3usME.

I think the text you're referring to is called "Battle Messages" in the ROM map on the wiki. The "Small Captions" and "Big Captions" in FF3usME are called "Short Battle Dialog" and "Long Battle Dialog" on the wiki.

https://www.ff6hacking.com/wiki/doku.php...sm:rom_map

Long battle dialog is usually associated with battle events, while short battle dialog is usually associated with monster A.I. Like Subtraction mentioned, the battle messages are mainly for system messages and spell effects. The index for battle messages above 0x45 correspond with the index for the attack. For example, attack 0x9B "Dischord" corresponds with battle message 0x9B "Level is halved".