It's not unicode, but there's also sixelplot [1] which allows matplotlib plotting in a terminal using sixel. The underlying pysixel library [2] unfortunately doesn't support Python 3.7+ however.
Honest question: Why would I ever want/need to plot data in the R console, and not in a R graphics window?
the "work" you are doing is via ssh into a big box behind gateway/jumphost with peculiar limitations on ports & access from the data gravity well which is your bog standard asymmetric home isp ; annoying but you need to do anyway because the remote hardware has more bandwidth, memory, cores and storage than a stack of laptops taller than you... I could go on but lets just acknowledge not every task fits in a prepackaged shiny solution.