I don't think I can do the two character thing after Smile. The whole cast needs to be together right from the start. lol
Heartcatch gets away with it a little more by virtue of the fact that they have a lot of guest characters of various degrees of recurringness. To be honest, whilst I've been liking the monster design in it, I think it's something that DokiDoki can learn a lot from - the setup isn't that far from what goes on in Heartcatch, but if nothing else, it'd be neat to actually have the monsters somewhat tie into what's going on in the rest of the episode in DokiDoki more often rather than be mostly random outside of Letter Goat.
I kind of feel that Smile did the whole self-aware humour thing considerably better as well, even whilst being considerably more blatant about it. It's part of my larger problem with DokiDoki in that it hasn't really displayed much personality, at least not of it's own, up until this point, and it's only really with this most recent episode that it's feeling like it's finding it's feet. I'm still not really sure what's supposed to be setting this Precure apart from others, though - I suppose it's showing a much more rigid continuity compared to most of the others, so I wonder if it's going to keep that up across the course of the run.
Also, whilst DokiDoki's humour and direction seem to be gradually improving, it's hard not to notice that, regardless of story content, pretty much any episode of Smile felt more ambitious production-wise - the animation was considerably better, and everything was framed in a far more dynamic fashion. Can't help but wonder if DokiDoki is suffering due to Toei suddenly realising that they're supposed to be remaking Sailor Moon.