OK, played around and got the basic VLAN setup.
The SFP GPON lit up and I was able to configure the VLAN35 (TAGGED) on the SFP port48. Port 46 was VLAN35 (UNTAGGED). Port 44 VLAN1 default setup. All other ports were kept as VLAN1.
Optical go into the SFP GPON port48. CAT6 cable plug into port46 and other end to WAN port of the XWRT. CAT6 from LAN port back of the XWRT to port44 of Baystack.
All home network on VLAN1.
This was able to get me to my standard setup to get internet bypassing the provider hub/router.
A more detail question would be if there are any special settings to maximize throughput of the gigabit fibre.
As a comparison
1. Using the built in speedtest inside provider hub interface result in 1.1Gbps/900Mbps.
2. Using double NAT (2 separate subnet) provider hub (using PPPOE to authenticate) LAN to XWRT router, speedtest drops to 950Mbps/600Mbps
3. Remove the provider hub altogether and using the SFP ONT and using the XWRT to authenticate PPPOE, teh speed drops to 780Mbps/780Mbps.
Any comments or suggestion would be appreciated.