A fire curtain is designed to prevent the spread of fire - heat and smoke. I wonder in whose opinion it has been over engineered? Is this the holder of the purse perhaps? You are correct in saying the FRA will determine if it is needed, has there been a material change in the premises that would take away the need for the curtain perhaps? Public access facility - I would think twice before taking it out - you may find that if repairs/spares are expensive or difficult to obtain it may be cost effective to have a new, more modern design type installed? Have a look at the fra and ask the fire risk assessors their opinion and will they put their name against any decision to remove it.