Hello! Thanks for your interest
New Game+ plugin itself does not provide a functionality to change the title. But I have a separate plugin to change the title graphics over the course of the game:
https://рпг.укр/плагін/GRB_TitleChanger.js
I haven’t made an itch.io page for the Title Changer plugin yet (there's only an Ukrainian wiki page for now), but the plugin is quite simple. Also, there’s in-editor English description (just make sure you read the section for MZ, because MV works a little differently).
You can combine the two plugins: just use 2 plugin commands in relevant moments (one to enable New Game+, another to change title), like this:
◆Plugin Command:GRB_NewGamePlus, NewGame+ ON ◆Plugin Command:GRB_TitleChanger, Set title images : :Title 1 = Town1 : :Title 2 = Medieval
Hope that helps.
—Dmy from Garbata team