On a late 2015 27" iMac. (my first!) Is it safe (or OK) to leave and SDXC card inserted all the time? Wondering if the OS writes to the SD card when it is not being accessed by the user. I have the 512GB SSD configuration and figuring out my plans for additional storage. I'm looking at adding a SanDisk 256GB SDXC, if feasible. Thanks!