It wasn't clear if the target is to get him into public school next year. If not, then maybe let his asynchrony catch up a bit before handwriting practice?
Perhaps strongly encouraging drawing to help with fine motor control?
Or maybe get a plastic stencil for lettering? We have one with the captal letters and shows the sequencing numbering for the strokes as well as the direction to move the pencil.
If the resistance isn't the writing as much, I wonder if it is mainly a push to get more responsibility/choice in the process.
