First thing, I think you might run into this same problem in a non-Montessori school - it was a problem for us and our dysgraphic ds in elementary school until we had a clear diagnosis and were able to advocate (strongly) that ds shouldn't be kept from recess/free time etc as a consequence of not being able to produce written work quickly (our ds' challenge).
It's not a good situation - for a lot of reasons. First, it is in some ways punishment for having a challenge. Second, it doesn't help remediate the challenge if he's not receiving help for his challenge but just expected to be able to produce the same work in the same way at the same rate as every other student. Most importantly, you need to be sure it's not silently eating away at his self-esteem or feeding into anxiety - those impacts can go unnoticed until they build up to a larger-than-they-need-to-be level and going forward, those are the impacts kids remember and take to heart every bit as much as their actual struggles with LD etc.
I also do not know much about dyslexia, but for a dysgraphic child (or at least for my dysgraphic child), having him correct his backwards gs over and over again wouldn't have taken away his dysgraphia, and wouldn't have prevented him from writing them in the wrong direction the next time he had a writing assignment - so what would have been frustrating on one level for a child who isn't dysgraphic (making the corrections, which DO happen for some kids still in kindergarten) - for a dysgraphic child it's going to be 10 times more frustrating because it's not going to make it necessarily easier to form the g tomorrow. I'm not saying that having a dysgraphic child practice handwriting isn't worth the time and effort, but I think it's really important to understand the challenge going into the work and to put together a reasonable plan for remediating rather than just going about it the way you would with a neurotypical student.
I also don't know if this is true for your ds (or if he is even dysgraphic) but - for some dysgraphic kids (my ds is one of them) handwriting HURTS. Real, physical pain. And kids don't always tell you that - I had no idea until he was diagnosed and we knew to ask about it (when he was 8 years old) and we found out it had always hurt his hand to write. I also found out again, at 12, that handwriting was hurting again and had been for awhile, even though he very rarely uses handwriting anymore. He knew it hurt, but he didn't bother to tell anyone, he just went ahead and wrote by hand when his teachers told him to.
I would love to have my ds see the Eides - I think their insight would be fascinating and invaluable. OTOH, we weren't able to see them - we live elsewhere, and when we've had a reach at the opportunity their appointment books have been full. In your situation, I'd so want to wait and see them - but otoh, if my ds was struggling in school now, from what you've written, I'd seriously rethink if perhaps it's not worth seeing someone else that you could get an appointment with sooner. We didn't have the Eides, and we didn't have the option of seeing a neuropsych who specialized in gifted or 2e kids... but we still were able to get so much info and help from our run-of-the-mill plain old doesn't specialize in anything other than kids neurospych. If there's one regret I have at all re my ds' early early years of school, it's that we didn't know for sure what was up sooner. I am not at all certain we wouldn't get exactly the same advice from the Eides we received from his neuropsych.
Having a professional diagnosis and advice from *someone* might really help your ds now - and help you advocate for what he needs at school. Do you think there's any possibility you could go for an eval now and still see the Eides? I know that would be extra $ and a lot of it!
Just thinkin' sorta out loud
polarbear
ps - re when to tell your child they might have to work harder and longer for the same result - your child probably already knows it. What's going to help is to have an official diagnosis, something you can tell your child for certain that you know, in order to explain it. Just telling your child that he's going to have to work longer and harder may sound (*TO HIM*) like it's his fault, or something's wrong with him, or he's not as "good" or whatever or "smart" as his classmates. But if you explain to him what dysgraphia or dyslexia is it's putting the "fault" elsewhere - it's letting him know it's not something inherently wrong or "bad" or whatever about him, and it's also a way to let him know there's a gameplan to remediate and accommodate and that you're going to be there working beside him to help get him where he needs to be. I don't think that's a good conversation to have until you know for certain what the challenge is - but that's jmo.
Also, fwiw, one thing that helped my ds a ton was sharing examples of adult dyslexics and dysgraphics who had perservered and are successful. There was a common thread running through most of their stories - school was a struggle, especially in elementary. Many times teachers and other adults in their lives didn't understand or see their struggles. Many of them had a parent who made THE DIFFERENCE in their life by believing in them. And that's the thing that has also made those conversations easier for our ds (and for me) - you have to talk about how it will be tough and hard and take a lot of work, but you can reassure your ds you're in it with him for the long haul and most importantly, that YOU believe in him even if no one else sees the strengths yet. And that someday, those strengths are going to be what the world sees, far more than the challenges.
