There's also the Microsoft probe/beacon extension that exists. https://docs.microsoft.com/en-us/windows-hardware/drivers/mobilebroadband/network-cost-informati

There's also the Microsoft probe/beacon extension that exists. https://docs.microsoft.com/en-us/windows-hardware/drivers/mobilebroadband/network-cost-information-element https://docs.microsoft.com/en-us/windows-hardware/drivers/mo... I don't know what iOS is doing, as they still didn't have proper data metering and limiting the last time I checked.