I think that a lot of people think that PIP assessors know about the disabilities that they have. They often don't. They have a decision maker's guide that gives them an overview of many conditions. They have a 'medical team' who they can contact for advice. But they often won't know about the specific condition that the claimant has. Then, of course, within any condition there will be a spectrum of severity. That's before you get to overlapping conditions that increase the severity of the claimant's needs.
I have 3 children with SEN and I always fill the claim forms in as if they have never heard of their condition. I spell out every detail of why they need assistance/supervision/prompting with each activity. I explain what would happen if they don't get that support.
I've found, anecdotally, that PIP is better for ASD than DLA. One of my children got high rate care and low rate mobility for DLA, then Enhanced for both on PIP. One got middle rate care and low rate mobility for DLA, then Enhanced for both on PIP, and one currently gets middle rate care and low rate mobility for DLA and will transfer to PIP later this year.
You really can't use logic. You have to be really explicit and look at the wording carefully. For example, if you start telling them how difficult it is to prepare a Sunday Roast for the family, when the criteria is a simple meal from fresh ingredients for one person (such as an omelette), then you'll score no points. They don't care if you can't bend down to the oven, or if you can't lift something out of an oven, because the criteria is based on using a hob. They don't care if you can't lift a big pan of boiling water, because the criteria is a meal for one, and they would expect you to scoop the food out of the water. So you have to look at what the criteria is and how you meet that.
People with learning disability/mental health needs often meet these criteria more easily because the cognitive skills required for cooking, such as knowing how high to turn the heat, knowing how long to cook something for, knowing how to check that it's cooked, knowing what to do if it burns, remembering to turn the heat off after cooking, and knowing what to do if it goes wrong, make cooking a risky activity that may require supervision or prompting.