You can remain online while using Spotflux (despite being free, there are no limits in place that prevent this), but I'd recommend only using it when you want to play the game, lest you accidentally purchase something via a Steam Store intended for a region that is not your own. Disabling Spotflux will cause the game to revert back to its previous locked state (in the Steam Client, that is -- you won't be booted out of the game itself), but reenabling the VPN and restarting Steam will fix this. Also be aware that although there have been no reports of VPN usage drawing the ire of Valve in cases where you're
not actively attempting to bypass the Steam Store of your region, use of a VPN at all is technically against the
SSA.