It would be awesome to hear/see more about the system you built to auto-generate and submit evidence. This is a huge pain for many companies which an open source tool could solve.
Formal 1 page letter with company logo - "Dear Sir/Madam.. writing about $9.99 dispute for card XXXX on X date for user [NAME]" (all this is pulled from the Stripe API).
I then have 5 appendixes on separate pages:
Appendix 1: Users' receipt (just a pic of the Stripe receipt)
Appendix 2: User's order history (just printed, name of items, price, and timestamp)
Appendix 3: Screenshot of the user's purchases page clearly showing the item
Appendix 4: Email confirmations - I store copies of each HTML email sent, so just take a picture of this.
Appendix 5: Site activity with IP addresses and timestamps. This is all user actions on my site (viewing items, purchasing, etc.)
I created it because I had 20 disputes piling up, and I was dreading processing them all. Given that you're likely to lose the majority of disputes, it's super discouraging to put in the work, but this makes it a bit easier (I don't want to let fraudsters just get away with it!).