The research has been complicated in the US because so many of the cell lines pass through fetal tissue. But IIUC it's ongoing (and not so encumbered in other countries). Not to say all are intertwined with fetal cell research, only that it's one of the cheapest sources of stem cells and law has made using it complicated.
Almost definitely: livers to implant need to be full sized and last years to decades. A test liver could be 1cm2, fit on a microscope slide, and have a two week shelf life.
Not to mention that there is a much higher bar, ethically, regulatorily, and economically for testing a synthetic implantable liver vs a 'liver-on-a-chip'.