0v0, 10 months ago I think glider can do this, with -strategy rr (Round Robin mode). I have not used it in this way myself, so you might need to experiment a little. Proxychains can also do this, but it doesn’t present a socks5 interface itself (it uses https://stackoverflow.com/questions/426230/what-is-the-ld-preload-trick, so it won’t work everywhere).
I think glider can do this, with -strategy rr (Round Robin mode). I have not used it in this way myself, so you might need to experiment a little. Proxychains can also do this, but it doesn’t present a socks5 interface itself (it uses https://stackoverflow.com/questions/426230/what-is-the-ld-preload-trick, so it won’t work everywhere).
-strategy rr