I agree with Paul that a pragmatic surveyor will interpret relevant to vessel as found.
You may though find that many surveyors are well experienced deep sea masters or chief engineers and will value the use of a simple mechanical system to slow down and eventualy stop fire.
The fact is that the surveyor has, on sight of the vessel, put this forward as his prefered option. Putting to the surveyor the paragraphs of the coding may not be the best solution when a simple engineering solution is available. ie. curse, groan, do it and smile !!
If I remember rightly (and happy to be stood corrected) the fire flaps are a requirement under SOLAS chapter 111 and the harmonised codes require any RIB over 8m to be built to a standard of SOLAS chapter 111. Thus a big can of worms can be opened here.