I get that if the ethernet is correctly up but the host can’t get an IP address because the host is expecting to get an IP address via DHCP but there is no DHCP server. However it is not clear to me whether you are getting the ethernet to come up in the first place.
It is probably not worth your BTC. Spend the BTC buying such an adapter that “just works” out of the box.
I use a tplink UE305 (cost: not much - far less than 7 hours of your time) with my Librem 5 running PureOS and it just worked out-of-the-box. No messing with firmware. No messing with kernel parameters. No stuffing around. (I believe that this dongle may have been superseded by the UE306.)