I don't think the pacing was sped up simply because readers weren't interested. During the first several dozen pages of DD, even many of the supporters complained that the story was progressing too slowly, and the number of likes was relatively low. Despite that, the pacing remained unchanged.
With Baker Dozen, however, each episode can last for several pages before suddenly skipping ahead by a month or even three months, which makes the overall progression feel much faster.
It makes me wonder if the original plan was changed because, if both ongoing comics progressed at such a slow pace, the creator might have been worried about losing supporters. By making Baker Dozen move faster while keeping DD slow, they can balance the two series.
If that's the case, then it actually makes me think DD will continue to maintain its slow pacing and end up becoming a very long series, potentially spanning several hundred pages.