I don't think that this (the triple sole) would be a good option for kneeling down with your toes bent. Celastic toes and toe caps also make this worse. This is a pretty thick sole. It does however, give a big heavy guy plenty of support for walking and standing.
For work boots, I went with distressed rough-out, single midsole, unstructured toe, and the honey vibram soles. That has plenty of flex to do what you mentioned.
I'm thinking about ordering a pair with Honey Vibram - what's the heel & heel height on your pair? Thanks!