There’s always room for improvement, you know—
it’s the biggest room in the house.
[Louise Heath Leber]
I’m still experimenting with the replaceable sole. This is a photo of an anklet/bed sock that is my latest attempt. Notice the line along the join between the sole and the upper in the photo in the post below compared with the join in this photo. Instead of making the join by knitting together the edge stitches on the right side, I purled them together on this anklet. That puts the line on the inside of the sock.
Knitting, writing and other joys 
Someone else mentioned that pattern. I’d not heard of it so I hunted it up and found it in EZ’s book “Knitting Around.” My goodness. Her mind must have worked in a very complex way. The soles on hers are worked around with all sorts of shaping, and they look like they end up in the middle of the bottom of the foot. They are like real moccasin soles. Mine are worked similar to the foot on a regular sock — straight from heel to toe.
I may be off base here, but have you recently looked at Elizabeth Zimmermann’s Mocassin Sock and related footwear?