It's been a while. The free (lite) voices available have been expanded (updated 11/13/21):
index - powered by h5ai v0.29.2 (https://larsjung.de/h5ai/) : Aiko Std, Chiyu Std, Eleanor Std, Genbu Std, Rikka Std, Rikka AI, Saki Std, Saki AI, Maki AI JPN, Maki AI ENG
Synthesizer V Studio Basic 及び...