English, Hepburn, English, Hepburn, alternating in OP and ED. Why?
This isn't unheard of and this is actually an older tactic than you may think.  Funimation's dub of Outlaw Star, for example, does the same thing has in the past done the same thing with its opening and ending songs, alternating between English and Hepburn.

For whatever reason, the dub on their site for free users no longer alternates.  Some older DVD releases do, though.

You surmise correctly in that this helps the English speakers follow along with the song, and understand the meaning of the lyrics, too.  The Hepburn addition allows non-native Japanese speakers to at least get a feel for how the words are pronounced.