I have been using Synthesizer V for a lot of my music and the quality is very high, even with little manual tuning. There are a lot of voices to choose from now, and they added a cross-synthesis feature which lets you use the voices originally intended for Japanese and Chinese in English, and they don’t have a strong accent (I do find that I have to mess with the lyrics input a little). Also SAROS is coming out which has experimental Spanish support.

Definitely recommend looking up some Synthesizer V covers to see how realistic singing voice synthesis has become in recent years. It’s also free to try lower quality versions of the voices.