haven’t tested range,i mostly stay within line of sight,shooting real estate,or roof inspections for insurance,haven’t noticed any interference at close range
i noticed you need a phone cover,as it feels like it could slide out without one,thats on iphone 7 plus and Huawei xt2 ,holding the fold down clamps counter balances the top heavy mount,i like it
if you’re unfamiliar with it i wouldn’t bother,you can really mess up a device,if you get an extra phone research and and do some trials,yes it can be risky but not if you know what you’re doing