Floor rules state that proxies may only be issued if the card is damaged DURING the event, no matter the circumstances. Not like I'm trying to be a wet blanket, but just sayin'.
Did you consider the last paragraph in 15.7?
In some cases, a card is damaged due to a production error. Players should do their best to
avoid playing with these cards, though sometimes that is not possible. If the judge feels that this
creates a marked‐card situation, the judge may create a proxy card to act as the damaged card
in all ways for the remainder of the tournament. The damaged card must be retained to use as a
reference when the proxy card is played.
If these cards are prone to bending, I'd call that "damage due to a production error".
Regardless, I think this is an area where we can be a bit flexible in the name of fun and fairness. I'm not going to proxy a card just because you don't want to play with it (avoiding damage is your responsibility), but if it's a key card, it's your only one, and it creates an issue through no fault of your own, and you bring it to my attention early, then I think we're okay in addressing that. "Too bad, humidity FTL" seems like a response contrary to the Spirit of the Game.
Here's one for you -- 11-year-old brand-new Senior player shows up to a tournament, skips the deck check, and in R1 is found to have an illegal deck. 56 cards, and all the Basics in the deck are out of format. According to the Penalty Guidelines, illegal (or missing) cards are replaced with basic energy. After doing this (according to the rules), you have left him with an absolutely illegal deck (no Basic Pokemon) that cannot be played. Technically, at this point your only option according to the rules is disqualification. What do you do? I can't name a single organizer or judge that would actually DQ him. We'd apologize, briefly educate him and the parent on the Modified Format, hand him a theme deck, and allow him to continue with that.
It is important for judges to consider the Spirit of the rules, not just the letter. While we must always strive to maintain the integrity of the event, there are areas like these where we can compromise without really impacting the eventual outcome.