honestly im so annoyed right now because I bought this a7C II specifically for my trip to Japan next month but everything I try to add to it just makes it bulky and pointless. My logic was that it would be a tiny powerhouse but the grip is so shallow that my hand starts cramping after ten minutes of shooting and the standard straps are just way too thick. I was thinking about those smallrig baseplates but then I saw people saying they block the battery door on some models and now im just stuck. I've already spent enough on the body so I need stuff that actually works without doubling the weight. What are you guys actually using that doesnt ruin the form factor?
TL;DR: Get a thumb grip. Be careful with bulky plates; i would suggest the JJC TA-A7C2 Thumbs Up Grip and a VKO Soft Cotton Camera Strap to keep it light and save money.
In my experience, you dont need to spend much to fix ergonomics. I have tested many setups over the years and these are the most reliable: