Getting a properly specified and quantified ECHP usually takes tribunal and then it's not implemented so SEN!SOS and JR. So we go for specialist school. Even for academically functioning ASD this is 5 GCSEs, no A levels.
High needs parents exist because the EHCP is not being delivered. OP is burnt out. Probably because support is not being delivered as it should be. Shes not even seen the EHCP. Impacting on DC, parents and her.
Imagine how parents feel when their DC 1:1 is used to support someone else. They may have involved paid for EP, SALT, OT at thousands to get a decent specified and quantified EHCP. A bit like paying for a gardener to focus on your garden but then the school comes along and gets them to cut your neighbours grass and trim their bushes rather than yours because they're more of an issue to them. But you paid and your DC needs are not being met.
The red flag is the need for DC to be 'independent'. This actually means left without support. There is no scaffolding and watchful waiting. It's literally being left to sink or swim because your paid for 1:1 is otherwise occupied. DS2 was left to doodle at the back of the class so he didn't disturb others. Not freelancing to earn more money for themselves but providing free labour for the schools they work in.
Given my experience of tribunal and failed specialist school for DS1 I was done with it all with DS2. He has not meeting expected achievement and suffering poor mental health from being consistently told off. He had an EHCP so LA funded internet school and I was as LSA. He is academically able ASD/ADHD. He got 11 GCSEs, went to brick 6th form and is now doing masters degree in mechanical engineering.
OP you should have sight of EHCP. You should adhere to EHCP. You need written directives where your employers want you to do different. Eg 1:1 specified for 25/32 hours in EHCP but employers said XYD. They're breaking the law, not you.