My daughter has a hard time wearing shoes. We can get her to keep them on only by having shoes with laces that are hard to come loose. While at home she will not wear them at all or socks for that matter and if she is in the car she wants them off as well.

In my daughters case it is a sensory issue and she will tantrum if we push her to much. Any teacher who works with ASD children should know this. I would bring this fact up to the teacher and if that goes no where go over their head with the principle. This is a small issue in the scheme of things and if the teacher is letting this get in the way of learning they are not to good at their job

Obviously, the first thing to find out is if the shoes are uncomfortable. At three, he might just be getting ready for his nap.

I think it may be time for a meeting with the school. The idea that a child is taking of their shoes to get attention seems unlikely to me, but I guess it is possible. If he is doing it for attention, then she is handling it all wrong by giving him attention.

If he is doing it to be defiant, then she is handling that wrong too. You can't browbeat an ASD kid into compliance. You have to redirect, and then offer some sort of bribe to return to the world of shoes.

Get her to ask him a question that he knows the answer to. Then, when he gets the answer right, praise him and give him a cookie. Then, and only then, offer him another cookie to put his shoes on.

If she doesn't know how to use basic ABA, then she might not be trained properly to do the job she is doing.

I would explore the reason. Spend some time and change the routine at/after lunch. Take shoes off for 15 minutes before lunch. Change the shoes (if you haven't already). Be sure it's about sensitive feet. While it's certainly a good idea to be sensitive to your child's pain, it's also going to be important that he learn how to keep his shoes on (eventually). Do so gradually, of course, with huge rewards for compliance.

my son use to hate wearing shoes would take them off every where got him the converse high tops he couldn't take them off

I have a student who likes to take her shoes off after lunch and honestly it's the least of my worries. I have one rule, she must bring her shoes with her if we leave the room. I don't require her to put them on, just bring them with her (you never know when we will have a fire drill or something that requires we go outside.) I am quite positive this is a defiant issue (she puts them on with no problem when she wants something like to go outside) but I really don't care, if I fight with her she wins so I just choose to ignore the situation with clear expectations. My principal stopped us the other day because we were in the hall and she was carrying her shoes and asked her to put her shoes on, she immediately stopped walking sat on the floor and started screaming. When I said "Kayla, stand up, pick up your shoes and follow me" she stopped screaming and followed. I told the principal what was going on and the principal apologized for causing trouble. I have bigger problems to tackle so shoes aren't an issue.