...firefighters often use non f/f lifts anyway subject to their DRA...
Just a point of info on this - if the lifts are 'modern' and compliant with BS EN 81-73 then once the recall signal is made, all car and landing calls (including keyswitches in the car) would be disabled, so this will not be an option. The only thing the fire recall signal does not over-ride is maintenance operation e.g. technician driving the lift from the top of the car or in the lift well. There's nothing you can do to move the lift until the fire alarm is reset.
Come across this sometimes when people try to 'risk assess' the use of non-evac lifts during a fire emergency - they don't realise they won't work if the fire alarm is sounding - and this includes staff overrides / key switches! Evac and/or F/F lifts are obviously different and can be over-ridden.
As I said, only an issue with modern controllers, but all relatively new lifts (and most refurbished lifts) will operate as above.