Consequences or pros and cons of adding server under vlan with out having self ip or vlan in f5.

If you want to add a node (server) to a pool which is not on a directly attached VLAN, you will need to add a static route on your F5 device in order to route to your server. This will have no impact on your chosen load balancing algorithm. You will also need to add a return route on your switch/router or use SNAT to ensure return traffic goes back to the F5.

If you want to have a virtual server on a different VLAN to your self IPs you can also do this, however you will need to make sure that your downstream routing devices know how to reach that subnet by adding a route via an F5 self IP. TMM will route internally to the correct virtual server.

You will always need at least one self IP on your device.