User blog comment:ヌヌハラ/alice-tools v0.2.0/@comment-45214281-20200313112813/@comment-45214281-20200316072256

Ok so I think I traced it back to the preconfigured font size. In the dictionary like structure in the game .ex file, there is a key "Ｅ＿メッセージウィンドウ.%D番.メッセージテキスト.フォントサイズ" (where %D can be a number between 1 and 4). I don't know why there are 4 but the main message box is probably one of them.