"USB 2.0 up to 480 mb/s trasfer rate" from the spec page https://iosafe.com/pdf/ioSafe-Solo-Datasheet.pdf
so it should be fine with common usb transfer. You'd have to use some backup in linux to usb and not use any installed software from iosafe.
Any backup is better than none. They are wrong in their claims by the way. It is not fireproof. It is fire-resistant. My safe is a bit higher rated but only if it is located at the outside wall of the home. Interior fire could reach well above that number listed. 1500 degree isn't that high but to include the water is pretty good. Tax returns, important copies of deeds, wills and such would be protected to some degree. Simple family treasures like photos or letters could be scanned and saved. Many businesses fail after a fire or flood because they loose so much data.