The fire service will read the panel as loft, void on which ever area, if there is any confusion or ambiguity to the location then to be agreed with BC and the local fire service to whether remote indicators are necessary.. it is dependent on the application, if you have say 10 in a loft or void in a large area then yes local remote indicators should be fitted, if however you can identify a small room and the panel will identify it as the void above then it may be acceptable to omit the need. It is BC and fire service subjective view and may differ county to county.
If in doubt fit them as I always do, given that BC znd the loca fire brigade will no longer accept any design liability regardless if they instruct it it is best to go belt and braces.