I have been riding the MKS GR9s with MKS LL size clips and nylon straps. I wear size 13 (USA) DCs and my toe overlap sucks with a firm lip seal. I pull the straps tight, and flip them open when I need to put a foot down. The flip tab is so big on the GR9s that they can snap off, as my right one did. Sometimes you have to step on the underside of the pedal. Doesn't really matter though, it's still easier for me to flip into the right than the left, I would attribute this entirely to dexterity, but I have a suspicion I'm not using the tabs at all.

As for the small toebox shoes, yeah, they seem to fit better into these clips. Sambas make my feet hurt cause my toes are all squished together. I haven't found a wider shoe with a small toebox. With the DCs (skate shoes) I'm using now, I can feel pressure from the clip on top of my foot, but it sorta makes me think I have better power transfer.