Illusory Script contract fraud

I have an idea, I am playing a classic contract-type fiend warlock very much a "sign on the dotted line and you will have ____…. in exchange for your soul" and I was planning on using Illusory Script for contract fraud and want to know if it would work. For example, I write up a contract that says "I (warlock name) will give you a cup of tea, in exchange, you (victim name) will give me your soul… sign here _____" But then use an illusion to make it bog-standard fair contract. Obviously, the areas you sign are the same on both versions. Are there any obvious issues or workaround I would worry about?