How do they respond when you explain what you've already tried? Are they helpful in giving you input about specific issues you've mentioned? Sometimes it takes awhile for new therapists to get to know a child, and see what is going on, or what to try, but if you've been in for a few months you should be past that point by now.
It might be helpful to have them stand back and observe him with you a bit, to try and help get a better picture of him. Can you involve them in daily routines? It would be great for them to see how he does during tough points in your day, but since they're only there for a short time see if you can set it up to be as useful as possible. Is he tough to feed? Then have snack or lunch when the EI person is there, and see if they're willing to sit back while you interact with ds. How is he out in the community? EI therapists often will meet you outside the home if you set it up in advance.
Does your EI do child groups? Some have center-based groups in addition to the home services, and that can be a very different setting, and draw out different strengths and needs than individualized at-home therapies.
Part of the issue is he is just very different around other people (people besides me & DH) so they don't really get a true picture of him. It may very well be partly that they don't know him well enough yet too, he is hard to get to know and he's not really 'typical' in his types of problems. I haven't thought of having them kind of observe our daily routines... We've never even mentioned how he eats and it would be interesting what they might suggest when DS purposely dumps his water on the ground every. single. meal. and then cries that he has no water lol. The next meeting is around lunchtime so maybe we can feed him but I don't know, they always seem to have a plan to play with him, I don't want to interfere with their plans, you know?? And I don't really know what our daily routines involve -- it's really just meals and us playing with him... they have observed us playing and then they ask me to step aside so they can interact with him.
When we mention specific issues, they do have suggestions, but they are all things I've tried, which is not really their fault -- I've done a ton of reading. I can't seem to figure out if they are starting slowly and trying to feel out what they need to do to help him, or if they are just totally lost on how to help him.
It's an awkward conversation sometimes, but it sounds worth asking them outright. Ask what their plan is, if they have one, and what kinds of things they need to see. What are his goals on his IFSP? What strategies did they put down to help him meet them? Mention that you'd like some help with daily life activities, and ask if it would be helpful to do x, y, z while they're around so they can see. (meal, water play, getting ready to go outside)
When you say he's very different with you and dh, how is he different?
The big thing with therapy, especially EI, is that it should never be a mystery what the therapists are doing, why, or what the end goal is. It can be weirdly uncomfortable sitting down and saying that to a professional though - I always feel like I'm complaining, and criticizing when I don't mean to, but I've gotten to the point where I push past that, and am up front while also letting them know what I appreciate about what they're doing.
I think it's worth discussing what you have tried and how it went! The therapists should be most interested in what he does with you, since they are only there for a few hours a week and you are with your son all the time. If you have any specific concerns about your daily routine, like meal time, I'm sure they would love to know about it and would probably be happy to observe. As you know, kids learn through repetition and a big part of therapy involves repeating activities to maximize a child's learning potential. It may seem like they are trying and "failing" at things, but this all part of the process. I'm an SLP (working with the post-EI set) personally, I like parents to give me lots of feedback and I want to help them with their specific concerns. Have you considered video taping him to show his therapists?
He does have plan goals (to participate more in social settings, for ex., is one of them) but the treatment rec. is basically OT. I mean, they do write down specific strategies, but it's almost like a formality, because they know we've already tried them. The ones we haven't tried, we seem to have trouble integrating into our lifestyle I guess... which I've explained to them, I don't know, last week they said something about how he's really unique and they aren't sure what to suggest... although they are starting to see more of the issues we deal with since he is starting to get more comfortable with them, so maybe it will lead to something eventually. Not much time, he only gets 6 more months of EI...
Sometimes EI is worth it if only for the help transitioning to the schools, if that is something you want to try and do. It sounds like group may be worth re-visiting if the timing works out. As far as questions you could start with something like: "I only have you guys for a few more months, so I want to use our time as efficiently as we can. He loves playing with you, but I was wondering how (x activity they do every time) works on (his goals)?" Or "I wanted to look through the IFSP and tweak a few things. So, he has X goal, and we've tried Y, Z. Do you think he'll reach the goal before his birthday? What can we do to help him meet it?" If you think it would be helpful, see if they can write better goals now that they know him a bit better, and try if that helps everyone focus interventions on what really needs to be done.
If they're admitting they don't know what to do, it may be time to see if there is someone else from their office the could consult with. Are there any medical options, as far as further testing that would be appropriate or desired right now - psychologist, developmental pediatrician, etc.? Sometimes EI folks are in over their heads with kids who are unusual, and outside pointers can help.
One trick that works for some kids is drawing them out when the therapist is there but not engaging directly with them, if you want them to see more naturalistic behaviors. So scheme together for her to take a long time 'writing her note' as you and ds play/eat lunch/whatever, and she ostensibly ignores you, and you her. Or have the two of you consult as he's in the same room, and see if he relaxes when the attention isn't directly on him. You may have tried all of this already, but I figured I'd mention it just in case it's helpful.
My DD is very similar. She 'masks' pretty well until she knows you and then watch out! (She threw her shoes at the PT their last session and then sobbed for an hour b/c she felt terrible about it.)
We just had our EI assessment and I was actually surprised at how well they picked up on nuances of DD's behavior. I am so happy that they are going to help her.
To your question, I have no idea what you should do, but I think EI help is good. For us, I know having a different messenger than mom is helpful. DD will listen to other people over me sometimes and learns from others more easily from me (for me she just tantrums and goes nuts, I can't do much with her as her behavior is so magnified with me it obstructs her ability to learn from me). So that alone may be the value of EI for you.