Hi Kenny
Thanks for posting.
Any plugin can be used for Polestar but for Page Builder by SiteOrigin we recommend using either Polylang or WPML for your multi-language functionality. Polylang is free.
Loco Translate is mentioned in the post you’ve linked to. That’s also a plugin I’d recommend using but not for multi-language functionality, it’s for translating theme and plugin strings. So say your theme has English words embedded and you need the entire site to be Spanish, that’s where Loco Translate comes in.
I don’t have any experience with auto-translation so I, unfortunately, can’t offer feedback in that area.