prediction: in a few weeks somebody will rediscover the existence of tektronix emulation on xterm and the community will go crazy about it
I did not say it ironically! Tektronix is super-cool! It could be could be realistically rendered as sgv, and easily extended to add colors and stuff.
Some 3270 terminals also support vector graphics. I don't remember if x3270 implemented them.
And you'd have to translate the text from ASCII to EBCDIC.