I don't know what "bounces the interfaces" means.
You seem to be saying
"my USB to Ethernet adapter does not come up properly after the I use the networksetup or ifconfig commands to bring it down then back up again"
have you tested whether similar commands produce the right response from the same hardware on another platform? This might be a problem with the off-brand hardware, rather than the commands provided by macOS.
Topic:
App & System Services
SubTopic:
Core OS
Tags: