Yup, the dream machine. I haven't got it yet, was just wondering if there are other options since I read that Singtel's ONT + Mio TV can't work with UDM :/
You can try to request to change the ONT to ONR and then request them to bridge the ONR, telling them that you have the nice UDM which does not work with the ONT.
With a bridged ONR, no VLAN is required, you just connect the UDM to the bridged port and all features will be reserved.
Your SingTel TV box will need to be connected to the other ports of the ONR (unbridged, only for SingTel TV, no Internet access).
Take note if you do not ask for bridging of the ONR, you will have to live with Double NAT in order to use UDM as a router and not an AP.