I have plenty of spare tops so I really should experiment with that. I figure I should start with 0.02" since that's the width of the slots and then try your 1/32". I've sort of moved on from the block for now since the prototype actually works (surprisingly), but I'll eventually get back to it. I really need to get the case design sorted out so I've been back to working on that. I'll figure it out one of these days .