Jaguarundis are meant to make reasonable domestic animals. People have tamed them. I hesitate to say 'reasonable domestic companion animal' because I don't think a tamed wildcat, albeit a small one, can truly become a companion animal. I could be wrong but there is a barrier that prevents the kind of connection that you get between the domestic cat and the person. That barrier has been broken down by 10, 000 years or so of domestication. It takes a long time.
Which leads me to the difference between a tame cat and a socialised cat. A tame wild cat will be subdued and you can live with such a cat. The wildness has been more or less taken out of the cat. They become 'tractable' (capable of being controlled or led).
But a socialised cat has gone a step further to the point where he or she can relate and interact more with the human companion. There is a deeper connection. Socialisation takes place during the first 7 weeks of life of the kitten when the kitten gets thoroughly used to being around a person (and other animals if needed).
The difference is not black and white. They is a grey scale because a poorly socialised domestic cat will be similar to a thoroughly tamed wild cat.
I have met tamed servals (see: Morpheus and Penelope). One of the servals was socialised (neither Morpheus nor Penelope are socialised). However, you feel the wild character underneath the tameness. This is good. A wild cat should be that. They are at their best when magnificently wild; terrifying, aggressive, top rate predators and survivors. We are better off admiring them from afar. They are better off too.
If you socialise a wildcat in the same way you socialise a domestic cat, you get more than a tamed wildcat but less than a socialised domestic cat.