Yes, I am 100% aligned with you and could not agree more. It is obviously a financial move to get as many 60s turned up despite uncorking eligibility. Therefore, getting something in writing will be absolutely impossible! It's a crapshoot, but at the end of the day, you're still getting something out of the $2k investment.
Can you imagine me calling Tesla and asking for a written document offering me a refund for my upgrade if I am not eligible? I am sure that conversation would get a quick FU from any SC. If you have any experience with this or are willing to do so I am happy to compensate you for your successful outcome as the speed matters more to me than the range, to be honest...