Is ceramic fiber board necessary?

OK full disclosure, I am running an old school airtight stove atm and have not yet installed my ws-ts-1500 from woodpro. I bought it used for $200 and the guy claimed it was new and had only been lit once. I drove an hour to get it to find out I believe he hit the stove with his car while it was in the drive. It's scratched up on a corner, a few broken bricks and dislodged, and most notably the ceramic fiber board is cracked (it's two pieces but one is broken in 3 pieces).

I've never run one of these new stoves (insurance agent is whining about discoloration on my triple wall pipe, wood is as dry as it gets, I run creosote remover religiously). I'm impressed with the stove design as unlike most there's a layer of firebrick held up on the ceiling above the tubes, fiber board on top of the brick, then a hinged steel baffle that hangs down. It is my limited understanding that the fiber board traps heat and gasses for secondary combustion off the tubes. That said, with my stove having firebrick on the roof will my broken fiber board be an issue? I've read some old posts with people asking if a steel plate would work, it was decided that you probably don't want to stress and superheat your tubes but I have bricks against mine (and there's a 1/4in gap). Also considering fiber wool on top of the brick as it's cheaper but would still prefer to do nothing or cut steel plate.

Thanks in advance

http://downloads.hearthnhome.com/serviceParts/WoodPro WS-TS-1500 Service Parts List.pdf

MEECO'S RED DEVIL 5-pound Creosote Destroyer https://www.amazon.com/dp/B002PC274S/?tag=hearthamazon-20

This stuff is dynamite! Cheaper and much more effective than creosote logs as you can dump on as much as you need. Burn the creosote off till its flaky then give the pipe a good whack with the poker and it comes raining down. Problem I have is my triple wall cools at end and I believe the soot condenses in high humidity and in wind splatters off. It's not tacky tary creosote just brownish discoloration on top two foot of pipe. After a strong North wind I occasionally find light black fluffy soot balls on the ground. I've been on the roof as stove is running and gases are pretty cool to the touch, it's long and straight with strong draft...

I figure I'll piece the board together and put a piece of steel across it to seal the gasses if nothing else. I'm still going to be more efficient and go through less wood than I was.

Also fellas...listen to your wives. If they get a bad feeling about you going onto the roof listen to them. I got a 16 inch rod in my femur from a 14foot fall last year that should have killed or paralyzed me when I landed partially on the ladder (steep roof and was hanging onto pipe that came apart...stupid!). Be safe! Anymore I have someone stand on the base of the ladder and I climb up high enough that I can get to chimney without stepping onto roof.