I assume the use of the built-in teleport codes (for anyone who has the AGI release) is not allowed?

Yeah, no debug mode or cheat codes. (One runner did do a 1-7 collection run in debug mode recently though; so if you want to run the game(s) that way, there may be some interest.)

The AGI version has its own leaderboard: https://www.speedrun.com/kings_quest_iv_the_perils_of_rosella_agi