Thank you for posting it here too! I'm so glad with your comments and feedback, so much so that the new iteration will address most of the things you pointed out.
Regarding the tainted backpack square: if it was a Provision, yes, it remains there forever as a "stain". If it was an Ingredient, you can put it in your workshop and in your projects as normal, respecting the restrictions of a tainted square: you can't "craft out" that square.
Please let me know if that clarifies your question and thanks again!