Several routers can be connected to one ONT.
Several routers can be connected to one ONT.
It's feasible, simply connect it to the LAN port, turn on DHCP for every router, and it should function similarly to a switch.
Get a simple access point. I assume you wanted the DHCP server disabled. These systems often include routers with their own DHCP, which can cause issues if additional routers are added without proper setup.