Some operators (at least mine) gives the possibility to sett a different APN on the LTE modem, and this will give you a real public IP. That said, using a tunneling solution can provide better security.

From what I remember (I’m not 100% sure), my TP-Link switches has that option in the admin-interface. Model is SG108E. There are quite a few hardware revisions of these.

It is not a “full managed switch”, but what they call a “smart switch”, which have some configurable features.

What is the bottle neck you are experiencing?

Is sound like you think there is a bottle neck, but have not experienced poor performance indicating a bottle neck?