On my search to improving my A7C's ergonomic, I found Widget's camera grip for A7C ii/ R. I really appreciate the idea and printed one for fitting. Unfortunately, the grip size is different.
Fortunately, the base plate is almost identical so I only need to add a small smoother for it to fit nicely with A7C, and here is the model. The shape is designed so you can rest your ring finger on it.
The author remixed this model.
I added a small smoother for it to fit nicely with A7C.