Default [Q] disable network roaming, enable system select menu

Hi guys,

So on my n5 I have an annoying problem. Essentially the phone roams to another carrier (which is admittedly the stronger signal), but then I lose data.

I've seen mention of a menu called system select but its missing on my phone.

I'm rooted and running 4.4.3 with an earlier radio IMG which ironed out a lot of the network drops, so if I could fix this one last thing that would be great.

I'm thinking it might be enabled via build.prop but need your help...