Do you know you can now easily bypass Google FRP Galaxy S8 Plus, and S8 Android Oreo 8.0. It would help you to access your device if you have forgotten your gmail id after the reset or hard set of the device. http://www.techeligible.com/2018/03/05/bypass-google-frp-galaxy-s8-plus/
Hello pan198923! Regarding your concern, there are ways to bypass google FRP and they are not really specific on the devices you mentioned. I saw videos on youtube regarding this issue and I think that would be the best way for you to know how to do it. Goodluck!