It is possible to have another interface device, which pipelines transparently through all of the NAT crap, like you do when you use a VPN.
I am too rusty after a good number of years and would have to trial and error it, but just look up a good documentation of working with routing tables and you will be hanging your network nude to the world before you know it.
If you want to take it easy though just use one of the Maemo5 openVPN clients on the repos and pipe through a free protonVPN account or set up a VPN server or SSH tunnel on a non-NATed machine somewhere.
some low effort minimal review searching came up on DDG
https://medium.com/botfuel/how-to-ex...t-c31532d741cc
(edit)
This should give you what you need to set up a network bridge
https://www.linuxjournal.com/article/10929