That’s what the support person said to me as well, but I didn’t get that option when I tried to cancel the subscription. My guess is that it wasn’t rolled out globally just yet, so if anyone didn’t find this option you can just contact the sales team to downgrade.
My poor memory is telling me the heat is used to make the bits easier to flip, so you can use a weaker magnetic field that only affects a smaller area, allowing you to pack in bits more closely. It shouldn’t have the same problem as SMR.