Hello @fermin.
It seems like Firefox browsers was a problems in earlier versions with JS classes syntax support. You can see bug reports here https://bugzilla.mozilla.org/show_bug.cgi?id=1499448
It is fixed in Firefox now. Try to updtate your browser.
a) Ethernet will be present on the next EVCS HW versions.
b) We’ve had some discussions here [FEATURE REQUEST] EV Charger Option not Discharge Battery