Rebuildable UCA?

Yes. Moog is an aftermarket manufacturer. Along with many others.
Aftermarket is sometimes used to describe performance parts. Aftermarket simply means equivalent, superior, and sometimes less-than-equivalent to OEM quality parts, NOT manufactured by the OEM.

Better than OEM? I say yes. Rebuildable bushings and grease fittings sway my opinion.

It sounds like you may have creative steel polyurethane bushings . You can look at their site see if they look like yours . Are they red or black ?

I have creative steel polyurethane. Its a pain to get the originals out but once you do the poly bushings just slip right in. I did it the first time on old control arms and ended up replacing them again due to the ball joint getting loose.

Yes! These are the ones I have. They are black.
they were squeaking and my steering felt loose. They were greased and I could not see any visible wear. Are they superior to the Moog?