Simpsons Question: U.S. Animation, Inc.?

[Classic Speedy]

Quick question. The Simpsons Season 7 episode "Radioactive Man" is somewhat of an oddity in the pre-digital age in that it uses "electronic ink & paint and digital composing", according to the credits. As a result, the episode looks much cleaner and sharper than most Simpsons episodes of the era, due to the digital work. And the movement of the characters seemed much faster than usual, like it was Family Guy. According to snpp.com...

The animation in this episode

Tom Mannion forwarded me a post from Chris Cammack which stated that
"Radioactive Man was rendered on a Silicon Graphics (SGI) Onyx
Workstation with a fancy animation program. With a SGI reality
engine as a sever, this computer could animate an episode in Real
Time! Don't worry, the software had a modification to emulate old
fashion animation and they have used test scenes in earlier
episodes. This is something of keeping your eyes out for." Several
readers commented that they felt the animation in this episode was
substandard.

The overseas studio is Anivision, but it also uses a company that I've never heard of: U.S. Animation, Inc.

Does anybody know anything about this company? Have they done other work? Why didn't Fox use this company for other episodes?

[Classic Speedy]

Sorry in advance for the resurrection...

Seems like U.S. Animation, Inc. also worked on "The Simpsons 138th Episode Spectacular". I guess because there wasn't very much (or complicated) animation inbetween the many clips, an overseas studio wasn't needed. Apparently "Tennis the Menace" used some pre-Season 14 attempts at digital coloring as well, though I don't recall what company they used for the coloring in the credits. Was THAT episode by U.S. Animation, Inc. as well?

Incidentally, I sort of answered my own question: U.S. Animation, Inc. is a software company that publishes Toon Boom Studio.