As already mentioned, I do not recommend going with Singtel due to the use of ONR. If you really want to go with Singtel, none of the two routers mentioned are good in terms as a mesh solution. You have to go with other mesh solutions as I believe single router will not work for you. Linksys E9450 is fine as single router but mesh performance is not good.
Reference:
https://forums.hardwarezone.com.sg/...sy-mesh-router-e9450-e8450-and-e7350.6407984/
If you go with Starhub, they give the Linksys Atlas MX2001 router, which is also not that great. But you can go with it if you really want, at least the mesh should work.
https://www.starhub.com/personal/broadband/routers.html
So between Singtel and Starhub, Starhub is a better choice if you prefer to get router or mesh solution from the ISPs. Typically Singtel and Starhub do not really provide good mesh solutions and M1 will be a better choice in this aspect. But anyway, I usually recommend people to get their own router or mesh solution and DO NOT use ISP issued router as a criteria when choosing an ISP.
Reference: please read the first post of the following thread.
https://forums.hardwarezone.com.sg/threads/singapore-isp-comparisons.6665380/
5) DO NOT USE the FREE BUNDLED ROUTER as the base for choosing ISPs. In general, it is better to buy your own router as the free router is not really good. Or in some case, buy the higher end router from the ISP if it is a good deal (eg: M1 GT-AX6000 is a superb deal). But anyway, this is just my personal opinion and many are still using the free router as the base for choosing ISPs because they may rely on ISP to provide the technical support (even though the technical support is in general not good).