Shooting:
One thing I have learnt from my and others experiences is that in state or private schools if you have a child with SpLDs you have to be constantly on the ball, acting as facilitator, investigating options, correcting misapprehensions etc etc etc. it shouldn't be the case because pupils without the advantage of a proactive parent definitely lose out.
And many DCs, including, frankly, my own, don't have that. Despite my own superb olympic standard coping strategies (I wouldn't be able to hold down my job otherwise), there is only so much that I can do and cope with and my actual job usually exceeds that 'so much' point. I do not have the wealth - either in time or money - to provide the sort of full time fixing you describe. Most people don't. Being dyspraxic myself doesn't help. Having 3 kids with varying SpLDs doesn't help either. For one, I could manage, I think. Maybe. People with financial resources hide behind the label of 'proactive' but what they actually mean is, they can afford to do this stuff. It's not that they are better, it's that money makes everything easier. Everything you describe about your DD's experience screams privilege, to be honest. And ROFL at 60 miles outside London being 'the sticks'. Try 200 miles.
But - thanks for the info about post 16 assessment. I specifically asked at DD1's school at a meeting we had with the SENCO about DD2 (who starts there in September) and was told that definitely she didn't need any more assessments. Her last one was done at 14. She is only just 16 now so she will obviously need another one although I have no idea where or by whom that will be performed. As for attending university open days - not really an option for a FT working parent. Especially when everything is so far away - in fact, I strongly doubt that DD1 will attend many open days, the cost will be prohibitive and the travel challenging even for a person without dyspraxia (our trains are very very bad and also extremely unreliable). The thought of having to engage in protracted email discussions with up to 12 institutions (she will be applying to conservatoires as well as universities) makes me literally weep.
You are so right about the constantly having to correct misapprehensions though. DD1 got excellent marks for one of her AS subjects this year (she is in a 3 year 6th form) and the only comments on the report about this subject were essentially that she should stop being dyspraxic (that's not what the teacher said, obviously, he talked about being more organised as though that's a choice she can make). He doesn't help her in this respect at all - he only ever emails me to say a piece of work is late when the deadline has been missed (and on each occasion the work has been done, she just hadn't been able to email it in (the school wifi won't let her access the network, she can only email work in from home for some ridiculous reason and her lack of organisation skills means she sometimes forgets). He has taught her for the last 4 years and we have talked to him ad nauseum about what being dyspraxic means and he still resolutely refuses to regard it as anything more than dodgy handwriting and frequently walking into door frames instead of through doors. I think we are all (DD1, DH and me) on the verge of just giving up, to be honest.
I actually wouldn't mind so much if it was a level playing field for everyone with dyspraxia, as it was in my day (when the condition hadn't even been formally named and recognised). If everyone just had to suck it up and grit their teeth and stand up and get on with it, then that would be, within the group of dyspraxic people, equality. Not with non dyspraxics, sure - but at least among themselves. But it isn't. Some get support and consideration that others can only dream about. And that is just plain wrong. And it really doesn't help when people who have benefitted from rolls royce consideration tell those with morris minor or worse conditions that it's their fault, or their parents fault, or that in fact everything is actually fair and fine and they are imagining a disparity in treatment.