Sweet, sorry im not really familar with your situation, other than what you have posted to me over the last few days, so forgive my not being totally up to date, i havent been around for a bit.
I would say lodge your appeal, you have plenty of time to add to it.
This is my 2nd SA request, but 1st time round, i lodged my appeal, then wrote to LA telling them i had lodged my appeal and asking them to reconsider, using some of the points of my appeal and they agreed.
Im sure when the LA receive an appeal, it is just put on a pile and someone looks at it, just before appeal is due to be heard and they then decide, oppose or not.
I didnt get notes of 'panel' meeting, as i dont think there actually is one, its the named officer who decides.
This time round i have my SA Tribunal in a couple of months, i had already lodged my appeal before i asked for copies of school file and LA file etc. I found something rather interested on LA file from my 1st request for SA, the named officer was actually drafting a statement, then that all changed and they refused to issue a statement. I wont be telling the LA about this info yet, but saving it for the last minute.