I understand the importance of the foot bending at the ball while walking. My job involves a lot of both bike riding and walking. I rode in sneakers/platform pedals for years to address plantar fascitis in one of my feet. Walking in stiff soled shoes definitely hurt my feet but the condition has been resolved and I'm back on clipless pedals. Knock on wood, there is a risk of re-injury.
I've had touring shoes that were designed to flex at the ball but resisted bending in the opposite direction.
One problem with clipless compatable shoes that flex is breakage. I had some early pairs designed for casual use, more dual purpose on/off the bike which were not as stiff as performance models but they broke in half. Newer clipless shoes for recreational riders seem to be much stiffer, but rocker is sometimes added to make them easier to walk in.
You should try to ride in your running shoes. I never noticed a big problem with my feet bending too much around the pedal (flexing the opposite direction) when I was riding in sneakers. You can control that with the muscles in your feet. I did use big pedals though to provide some support.
Ergon pedals might work well for you. Slap a pair of these on your bike and have a go at riding in your minimalist shoes!
Ergon pedals would look nice on Xela's 11 speed bike.