Still waiting on round two of these to hit Optics Planet (ordered Nov 2nd)
I found that the lever interferes with my grip and trigger finger position. I would have liked to use the lever, but re-installed the round button because of the interference. Next project is to make a small file cut on the round indicator and fill it with red paint so it actually indicates something!
If I recall correctly in the installation directions the pictures they use have a plastic ambi housing and they say you can also use a SEF housing.