For those with Mikrotik routers.. I can confirm that Michal Rok's solution works..
i.e. you need to initially set the mode to 'sta' (in /etc/config/wireless) to allow Omega2+ to associate with a configured AP. The default mode of '9' cannot seem to associate with the configured AP even though it is visible. The trick in Michael's solution is the switch the mode to '9' as the last step in the boot process, in order to get an IP address.

Stupid.. but works. Not a good start to the Omega2+ journey!