LB2120 Router or Bridge Mode?

I have an LB2120 downstream of a cable modem. All of the settings are default(router mode) and it has worked fine for years. The LAN port is connected to a Nighthawk MR60 MESH router, also working fine. However, now I am in the process of separating those connected devices that I do not want LTE backing up, connecting them directly to the cable modem through a switch. This also seems to work. But the downside is now that I cannot manage the 2120 through my desktop PC, although I can with my laptop connected to the wireless network. 

First, I want to know if there is any reason to put the 2120 in Bridge mode. The documentation indicates that is really how I am using it, but it has been working in Router mode. There seems to have been problems reported by the community with Bridge mode, also. Second, is there any chance, in Bridge mode, the my PC connected to the upstream cable modem can access the 2120 which is connected to the same cable modem? My tech support from Netgear has long since expired and I cannot find any question of this nature in the database. Thank you.