I don't really remember, probably it was just a dream but I thougt pj64k has/had 64DD support.
But in GoodN64 there aren't 64DD roms, aren't they?
Don't know, but it would b great, if 1964 1.0 Final would have 64dd emulation, like ZSNES' satellaview support.
In near future it could still b, that some (beta) 64DD roms (Zelda?!?

) leak the public and then it would b great 2 play them...