SSH Agent Permission Denied for Multiple User Accounts on Same Machine

I just wanted to follow this up with the answer I got from support and why this is a known issue that isn't going to be solved.

Windows uses a hardcoded named pipe that persists across sessions and cannot be shared. This is why when you are setting up SSH Agent on Windows, there is a step to disable the OpenSSH service so that the pipe is freed up for 1Password to use. On Linux/Mac, UNIX sockets are used which allow multiple instances to co-exist and this is not an issue on those platforms. 

They have considered a 1Password background service to act as traffic controller to the pipe for handling multiple instances of 1Password, but this introduces significant security problems that contradicts their strict per-user process isolation security model. They are not to say it would be impossible, but it does not sound like it is something they are pursuing at this time.

The only option is to make sure the pipe is freed up in one instance before trying to use it in another. This would mean signing out of User A before logging in as User B. Or fully quitting 1Password in User A before switching to User B. If both users are admins on the machine, then you could kill the other user's 1Password with an elevated script. None of these are ideal and they know that, but they're a bit stuck due to how Windows pipes work.