A:Answer Yes, it was a same concern that I had when I had to decide to buy. I also have to use for both operations and didn't want to format.(And my main device is a Mac.)
The answer is (as I figured out) if you go to Seagate website and download "Paragon program" for PC(Mac automatically works.), the PC recognises the external hard drive for Mac. I was told it's kinda unstable, so might need extra cautions, but working good.