Yeah...using anything other than an Apple Approved(tm) scsi disk (or, really, anything 'not Apple') was an adventure. One of my least favorite Unixen, frankly. SVR2 based when most of the world on the AT&T side of Unix was SVR3 (and SVR4 was just around the corner), some BSD bits tossed into the blender, coated in a not-very-good MacOS emulation layer. Congrats to you on your perseverance; I recall the TCP/IP stack was...challenging.

A/UX was created so Apple could bid on government contracts that had a "must be Unix and/or POSIX" checkbox (common requirement at the time). IMO, they should have either gone all-in on a "MacOS apps running perfect on a Unix kernel" and picked a better kernel, or done the Atari thing and tossed the legacy OS and gone all in on a "Unix on Apple hardware". Instead it was 'meh' all around.