I am using a recent version (1.020) pulled from whatever FW was current last July. And then severely mangled to make it behave with Kobo's kePub renderer, and to have very very restricted blank vertical space.
It has indeed been updated a tiny bit, the hinting, IIRC, which might explain how hard telling the difference is (as it depends on the renderer, the size, and the screen's dpi).
And as you mentioned a phone, both iOS & Android render fonts unhinted
.