Storing PSA cards in fireproof/waterproof safes/boxes

I just bought one of these to store some valuables in and I’m curious whether it’d be suitable for PSA cards. Quote from the manual:

Would PSA cards hold up inside?

Would they need silica packets to be okay?

Would they even be fine in a sealed container with silica packets inside and outside of it?

Feel like I might have to experiment with it first before I store anything too valuable in it.

I’ve always avoided waterproof safes for just that reason. They way my safes are situated and the way the internals are organized water would never be a concern in a flood or in the event of a fire that is sprayed down by the FD.

That being said you should be fine as long as you have some desiccants inside as they instruct and as long as you open it at least every couple weeks as instructed. Every issue I have read about in reviews is typically a month to months between openings with no desiccants and then their metal items are starting to rust or their paper items are moldy or mildew smelling. I do know some people who use them for various valuables and important documents with no issues but they do follow all the recommendations in the manual.