No different from any other fire protection installation that contributes to fire risk.
If there's a planned preventative maintenance (PPM) regime in place that involves competent persons maintaining the doors (in accordance with BS 8214) then that probably ought to give you comfort that they would do what they're meant to - after all if we were talking about a sprinkler system and there were comprehensive maintenance cert's available then as part of a FRA you probably wouldn't look too hard at whether the design of the system complied with BS EN 12845?
If, however, the premises were reliant upon the fire resisting doorsets to control fire risk, and there wasn't evidence of a PPM regime being in place, then it might be prudent to recommend that a) a 'benchmark' survey and assessment is conducted to indicate what performance is likely (FDIS-type activity); b) if necessary, remedial works are carried out to improve fire resistance performance; and c) a PPM regime is implemented.
What we've seen in the past few years is that the status of passive fire protection (PFP) has gone up significantly, and all the good stuff as regards maintenance and inspection that we've been used to applying as a matter of routine to the active fire protection has started to be applied to PFP - hence the FIRAS-type schemes for installers and maintainers and the FDIS 'qualification'. ASFP has contributed to this with all the guidance they've produced. That's as it should be, in my book - the fact is that when we design most buildings the amount of money we spend on PFP usually dwarfs what we spend on the active kit, & there's really no good excuse for failing to maintain it.
