I don't use ePub, so I wouldn't know. They don't show with ePubs? I didn't know Kobo renderers are *that* different!
OTF files I gave are hinted anyway. But I found out that TypeGenius (This is what it is called in Kobo, right?) works well with OTF too. So here is another Alegreya, this one is only named rightly (as in Kobo, machine show bold versions in the place of regulars)., original hinting, weight and spacing:
http://cl.ly/2J3H3Z1o440O