I did a quick research about the Cisco option , and it does look similar to oneconnect.
However, I don't know enough about Cisco CSM to confirm that works the same way as F5 oneconnect.
With the mask of 255.255.255.255, only the same IP will reuse the connection.
So, that is almost the same as not use oneconnect, in relation to what the server sees and the number of open connections.
Have you tried without oneconnect?
In case you have not read yet, he is the oneconnect overview solution:
https://support.f5.com/csp/article/K7208