OK I have to chime in here. I will speak from a first hand experience. My wreck happened on May 2 of this year as everyone knows. I was commuting to work at 8:45 in the morning. I was struck from behind while stopped by a truck. I can only tell you what happened from what I was told. I did not have any ICE info on me. They cut off my clothes at the scene. I was non responsive until they were transporting me. I could only then ask them to call my wife. I could not tell them her number or even her name. I only kept repeating please call my wife.
The EMT's only checked my wallet after a person who works in the ER that knew my wife and had seen us two weeks before the wreck, ask for it. She then started the call process. My wife didn't get a call until almost 10:00.
Lots of discussion here on where the ICE list should be. I hate to say it but maybe taped to your helmet. Pockets, wallets, tank bags, jackets I don't think they work. The one thing I know they had was my helmet, the officers handed that to my wife after she arrived at the hospital. They may have check it if I would have had my ICE info there.
If you're knocked out a SPOT is not going to do you any good, unless some one is with you. I still have a SPOT and will have it on me when I start traveling again.
I don't have a real answer for where it needs to be. But you can bet when I do start riding again it will be on my person in several different areas. Wallet, jacket pocket, bike windsheild, luggage, taped to my helmet.
Just some thoughts.