Any reason to access the ONT? How would I do that?

Got 1Gbps FIOS 9 days ago and pretty good so far.

I can certainly access the Quantum router at 192.168.1.1. I'm somewhat used to those settings from my 14 years with DSL and from the Quantum's user manual and this forum.

But is there any reason to access the ONT, and how would I do that?

Thanks.