Before today, if you happen to have a iPhone with unofficial Apple battery, your service might get rejected due to third party components installed as per their terms. However, there is an Apple internal document which reveals Apple now approves smartphone repair for iPhones with third party battery and this services will be launched globally from 7th March.
However, terms does comply for servicing such as battery must not more than 60%. If the iPhone battery ring has broken or unable to be taken out, service center now approves iPhone replacement by just paying the battery fee.
The new policy only granted on third party batteries iPhone but not other components modified such as microphone, USB port, volume rocker etc. Apple remains the right to reject your services if terms doesn’t meet.