'Magnetic Mat': stored in ToolBag with ThumbDrives, HD's, Laptop, etc?

The Magnetic Project Mat IF145-167 seems like a great addition to a Field Techs Tool Bag. Is it safe to carry along a Magnetic Mat long-term in a Tool Bag, stored for extended periods of time, next to various devices, RAM, Thumb Drives, External HD's, and a Laptop?

I'm cautious, but iFixit store shows it with HD and Phones on it 'during' repairs, etc : but what about carrying this Magnetic Project Mat long term, stored in your ToolBag, nestled next to Thumbdrives, Ext HD's and Laptops for a long term. What's the modern consensus on mild magnetic fields next to these type of delicate tech items for weeks, months on end?