Can I fake location using two phones with find my friends by swapping sim and leaving phone in place ?
Find my Friends reveals neither the name nor the type of the device being used to share your location. So you could switch the device being used for location sharing to a different phone logged in to the same iCloud account, or even to an iPad.
To change this:
- On iOS 11: Settings → Your Profile → iCloud → Share My Location → From.
- On iOS 12: Settings → Your Profile → Share My Location → From.
Lots more details on how to block location: Can my son block me from finding him with my find my iphone app?