If someone with expertise in psychoed evaluation, and who knows your child, isn't too concerned about the low PSI, then I wouldn't invest too much energy into something that doesn't appear to have IRL effects at the moment. I will clarify, though, that mental processing speed is not the same thing as fine-motor speed, although there is overlap in how we assess them. You appear to be describing yourself as having high mental processing speed, but low fine motor skills, which could equally be true of your child, based on the available data. Your SO, OTOH, appears to have slower mental processing speed (but obviously has strong enough overall cognition that it hasn't been an impediment to progress in any areas important to him).
