Not sure I understand completely what you are trying to do, however there would be no need to connect your scale to all devices. As long as you have the Garmin Connect app installed on all your devices you will receive the updated information from your scale. The Garmin scale transmits information directly over WiFi to Garmin and relays the data back to your Garmin Connect app on any device. The only time it is necessary to connect directly to your scale is during the first (initial) setup and this is done with Bluetooth no other time is this required.
If I look into Connect on my moble phone that I used for first setup I see that the scale is known to that device. If I use my tablet the the scale is listed as registered into my garmin account, but is not active on the tablet. My Fenix 3 can be connected to all my devices, so I ask me if this is possibel for the scale, too.
I think I understand what you are asking, the answer is no the scale is only ever connected to 1 device and then shared to other people who can create a profile. Your tablet will receive the data from Garmin Connect every time you weight yourself as well as all devices connected to your profile. The only time you need to physically connect directly to the scale with device is to change the WiFi settings, there are no other settings that need physical connection to the scale. All invites to other users can be done via the Connect app or Connect website. Hope this helps.
