If you have a conversation AI working that can remember previous chats, the next step would be improve on the guidance.
20 tokens saying what the AI can already do isn’t much to transform its behavior, and a startup isn’t founded by a magic sentence using another’s product.
If you can’t expand that to 200 or 2000 words detailing every operational mode and behavioral quirk, then you have not hit the wall or come to the skill level where you can put the same quality of information into a fine-tune training file or a knowledge database.