Perfect thanks - if there is follow up attachments should we flag they are on their way in the initial pack?
You can, but it doesn't really matter, as long as they arrive by the deadline. After that then the panel don't have to admit them.
secondly - what’s the opinion on examples?
for instance if you are saying child x struggles in a particular enviromment - is it worth giving an example such as “in June last year this happened and this was the outcome” or is that something to save for the face to face?
If it's strictly relevant and you have evidence, ideally, yes. If it's just a general observation that "if this happens, this could happen..." it's not very helpful. One relevant example may be useful, more would be labouring the point in most cases.
finally, is an appeal letter ever too long? On the assumption that everything is relevant and not repeating itself should you just put it all down?
Well - if you find yourself writing pages and pages, then honestly it's unlikely to all be relevant and suggests you could summarise. As a guide, most appeals get a slot of an hour, which includes the schools' case and all the questioning. Some do take longer but that's normally because something comes up that requires more indepth questioning or further examination. I would say it's rare that a case genuinely needs more than 3 sides of A4 (excluding documents of evidence).