That's not a radiation hardened chip, it's regular off-the-shelf consumer electronics. The "solar radiation" test they advertise is part of MIL-STD-810H. It tests whether the electronics survive regular sunlight on earth. The only ionizing radiation this phone is rated for is UV light.

At least if it had registered memory there might be an argument that it has some radiation resistance, but no it's plain old LPDDR4x.

Ulefone Armor 29 Ultra has the same MIL-STD-810H conformance with "radiation hardening", 16GB of RAM and a flagship Dimensity 9300+. Just not a removable battery.